FiiO has been quite successful with their X series of high resolution digital audio player. So much so that perhaps even they themselves didn’t anticipate that the company will have to shift its focus away from their portable amp business in order to keep up with the DAP demand. But with Apple fading grip on the pure DAP market, a new niche of higher end DAP is born from music lovers seeking a better device to replace their aging iPod. Well, maybe ‘new’ isn’t the right word here - the higher end DAP niche has been around since Hifiman HM801’s invention late last decade, but now it is in a new era of growth and competition. The significant of X1 is not in its technology or sound quality, but rather being the first 24bit / 192kHz capable DAP that is priced just under US$100. Does the affordability mean HD music isn’t just an expensive audiophiles’ thing anymore but rather going mainstream? It is probably too early to say with just one DAP, but it certain is one of the sign that the music world is moving toward that direction – and FiiO is on the forefront trying to catch a piece of the action with their new X1.
 

 

 
Spec
Recommended Headphone Impedance Range: 16~100 Ω
Dimensions: 96.7mm × 57.7mm × 14.1mm
Volume Control: Digital, 100 steps
Weight: 106g     
Display Screen: TFT 320×240
Analog Output: 3.5 mm headphone jack              
Left and right channel adjustment: 5 dB
 
Line-out Performance
THD+N: Less than 0.003% (1 kHz)             
SNR: More than 110 dB (A-Weighted)
Frequency Response: 20Hz ~ 20kHz
Dynamic range: Over 110 dB
Crosstalk: Over 100 dB (10KΩ @ 1kHz)
Line output Level: Over 1.46 Vrms
 
Headphone-out Performance
Output Power: Over 100 mW (16Ω THD<1%)      
                      Over 65 mW (32Ω THD 1%)
                      Over 8 mW (300Ω THD 1%)
Output Impedance: under 2Ω
Crosstalk: over 70 dB (1 KHz)
THD+N: under 0.004% (1 KHz)
Frequency Response: 20Hz~20kHz          
MAX output voltage: over 4.2Vp-p
SNR: over 110 dB (A-Weighted)
MAX output current: over 46 mA
 
Battery Capacity: 1700 mAh
Battery Life: over 12hrs
Charging Time: under 4hrs (USB 5V, 1A)
 

 

 
Accessories and Build Quality
Accessories wise, it is pretty basic. You will get some screen protector, a silicone case, plus a USB cable. There are some optional accessories you can buy them yourself, namely a flipping case, an amp stacking kit as well as 3.5mm interconnecting cable.
 
Build quality wise, the X1 is very solid. As the company third DAP, FiiO has most the design recipe figured out. To put it short, it is a shrink down X5 with the same scroll wheel and 4 corner button design. The use of mechanical scroll wheel has been tested on X5 before so it shouldn’t be a problem as far as durability is concerned. Since X1 is more compact, it feels easier to navigate without trying too hard to reach from one button to another with just one hand. To save cost and space, FiiO decides to build both headphone-out and line-out into the same 3.5mm jack. It won’t be a problem for user who only uses one of the function, but you need to be extra careful if you are swapping the function form time to time. You really don’t want to plug your headphone in when it is outputting line level signal. The front housing of X1 is made out of aluminium, where the back panel is plastic. Though the smallest of the X series, it is still fairly big in size if you were to compare it to a truly small DAP like iPod nano 7G. However, it is definitely still fairly pocket friendly and at most, feels like carrying a smartphone around, maybe even less. Last but not least, the DAP itself doesn’t come with any user accessible memory. You will need a micro SD card to store files and playback music. The good news is that the current firmware does support up to 128GB, which is the biggest uSD card you can find at the moment.
 

The UI functions similar to that of X5.
 
Navigation
X1 has the power button, reset hole, and volume up and down buttons on one side, plus the scroll wheel, select and return, next and previous buttons on the top. The firmware UI itself is pretty similar to that of X5 and designed around the scroll wheel, but simplified. You will find most of the basic functions available on the X1 as well, but not the more advanced USB DAC function as well as the gain switch. Given that navigation is fairly intuitive, I don’t want to spend much time explaining all the detail as you should be able to figure them out with just a few minutes of use (if not, read manual please). A few things that I’ll like to mention are (again) the headphone-out / line-out selection as well as the library limitation – basically the current firmware only allows 5800 songs to be add to the library (no limitation if you use the file browser), but FiiO is working on firmware that will allow for a lot more. Not sure when it will be released though.
 

X1's headphone-out and line-out FR curve.
 
Sound Quality
As usual, let starts with some basic measurement. RMAA reveals no issue at all. The frequency response is flat from 20Hz to 20kHz in both headphone-out and line-out. THD+N, SNR and crosstalk are all normal. Output impedance is measured and calculated to be 2 ohm, which is what FiiO has listed in spec. Though not exactly under 1 ohm, it is low enough that you shouldn’t have any problem with the majority of headphones out there. Current output is quite decent – not as powerful as its elder siblings but certainly among one of highest in the sub-$100 DAP market. Max voltage output on headphone-out is about 1.6Vrms and on line-out is about 1.5Vrms, which are not too far from the listed spec. All and all, the measurement indicates a fairly solid DAP.
 
Sound Signature wise, X1 can be classified as having a very classic FiiO house sound that is warm and smooth. It is obvious FiiO has decided that a warm sound will be more popular for the average consumer as opposite to a neutral and transparent sound signature (i.e. X5) that is more appreciated by audiophiles. As far as tuning goes, I’ll think FiiO has gotten the X1 just right. Regardless of the difference in sound quality, X1 is probably the most mainstream sounding FiiO’s DAP yet.
 

X1 next to E11K
 

A match made in heaven
 
So how is the actual sound quality? Well, it is a solid upper entry DAP. Even though it is the latest of FiiO DAP, it is not going to be as good sounding as the mid level X3 or top level X5. Overall, you are looking at a DAP that is roughly on par to iPod nano 7G and Sandisk Clip+ / Fuze. The major difference are of course the high resolution support as well as a more powerful amp section, but neither of them instantly translate to class smashing performance. If you are not listening HD music or using a fairly demanding headphone, you might not be able to hear any distinctive quality difference between X1 and other solid DAP around the $100 mark.
 
One of X1 biggest competition, in my opinion, is ColorFly C3. Despite showing its age and can’t match up to X1’s many features, it is still one of the cleanest, most transparent sounding DAP in the same price range. The only downside to its sound is that it doesn’t really have that great an amp section and therefore doesn’t give a lot of control and tightness when driving a headphone directly. But what it does excel is when it is used as a source to feed a portable amp. The signal is so clean that it doesn’t diminish its sound quality with double amping. Without an amp however, X1 still hold an edge. Even though C3 might be a better source, it is not to say X1 doesn’t scale up noticeably with a portable amp. In fact, I find that X1 makes an excellent pairing with the new FiiO E11K, and arguably can be almost* on par with a standalone X3 (*I don’t have a regular X3 anymore, so it is based on memory).
 

Size comparison (from left): iPod nano 7G, X1, X3, and X5
 
In Sum…
As I have said, you won’t find anything revolutionary in the X1, either on hardware or software. Nor will you find a giant killer that is going to sound so good that it will shame all other DAP in its price range. No, those are not what X1 is about. What you will find is just a very solidly built DAP that has all the fundamentals covered and then priced very competitively, designed to fill in the breach between the cheap ‘mp3 players’ of old days and the expensive audiophiles players of today. That is where FiiO is breaking new ground with the X1.

Comply foam tip should need no introduction at this point, as it has become a norm for many brand name IEM to include a pair of them. But what we are talking here is something new – or should I say something old that has been put to new use - Comply has been selling a special foam wraps called the ‘Soft Wraps’ for custom hearing aid for a while now. The idea is that, by sticking a piece of soft foam strip to wrap around / near the nozzle of the custom hearing aid, it will ensure a tighter fit. This is especially useful since custom mold – as much as it is custom fitted to the person, it is still mostly a handmade product that subjects to tiny imperfection. Sometime it is just a tiny bit loose that isn’t worth sending back for refitting. Other time it is caused by weight change and aging that alter the shape of the ear canal just a bit too much. Essentially, the Soft Wraps is a foam tip for the custom hearing aid. Now, Comply has adapted the same concept for custom IEM as well, calling it the ‘Custom Wraps’.
 

 
The foam strip themselves are about 2~3mm in height, 5mm in width and just a little over 40mm in length. The two ends are shaped with a slight angle. When applied to the custom, it is supposed to have an angle so the two ends never actually meet but rather twisted. The base of the foam is a piece of very sticky tape. So sticky in fact, you really don’t get a chance to reapply it if you did it wrong the first time as tearing it out will very likely destroy it. There is definitely a learn curve there. One more thing to note is that – you must make sure the sticky tape follows the curve of the custom mold and never try to force it to even bend slightly, or else there will be a tiny ‘bump’ forms in the tape and it will irritate the ear canal. The foam itself is pretty much the same as the foam used on Comply’s normal foam tip, which is very soft in nature. Just like any Comply foam, it doesn’t really last very long, probably only a few weeks on heavy use on each strips.
 
The position on where you apply the Custom Wraps is pretty crucial to get the ‘right fit’. Having the foam too close or too far from the nozzle will either make it too tight or not tight enough. I’ll say there is a chance you might not get the right position in the first trial, at least I didn’t. There are however 10 strips in each US$18 pack so you can afford to miss the first time. Lastly, and on the more obvious: Custom Wraps is designed for hard acrylic custom and not for soft silicone mold, and you shouldn’t use it when your custom mold is already pretty tight.
 

 

 
I used the Custom Wraps only on the right earpiece of my custom IEM as my left side is already very tight. The right side isn’t actually loose either, but I do need to make some minor adjustment every 20 to 30 minutes or so to make sure the fit is perfect, especially if it is a hot day with lot of sweat and earwax. I have the foam strip applied too far away from the nozzle at the first try but I eventually got it right the second time. It is pretty much a trial and error process. But once I had it right, it really does fit like a glove. The seal was tighten up and I don’t have to adjust it much anymore and I don’t feel any discomfort at all. The foam collapsed in such a way that I don’t feel any intrusion at all. I do however want to stress that you have to make sure the sticky tape isn’t bend or bumped up in any way to ensure maximum comfort.
 

 
All and all, the Custom Wraps performs as it should by ‘fine tuning’ the fit of a CIEM. It is definitely worth a try to CIEM user who are looking for the elusive last 5% of a perfect fit.
 
A thank to Comply for the preview sample.
 
For those in the US, you might have a chance to get some free Custom Wraps here: http://www.head-fi.org/t/736199/having-ciem-fit-issues-try-comply-foams-custom-wraps-for-free

[Impression] iFi nano iDSD and iCAN with a splash of iPurifer
iFi Audio has gained a great success over its Micro line of small sized desktop gears, and now it is pushing into the portable world with the Nano series. The nano iDSD is USB DAC that not only works with PC, but also has OTG support for the iDevice with OS7 (via camera connection kit / CCK) and Android that have USB Audio Class driver built-in (*for older Android that doesn’t have the driver, there is still a chance that USB Audio Player PRO will work). The nano iCAN on the other hand is a pure portable amp, but infused with the magical XBass and 3D Holographic Sound we have seen on the micro iCAN. Both are retailed under US$200.
 

 
Spec
 

iDSD nano
 

 
iDSD nano
Power Source: Battery/USB Bus power
                                DAC/Amp always run on battery
Battery Life: ~10 Hours playback*
Formats: 44.1/48/88.2/96/176.4/192/384kHz PCM
                2.8/3.1/5.6/6.2/11.2/12.4MHz DSD
                353/384kHz DXD
                Bit-Perfect DSD & DXD DAC by Burr Brown (1-DAC Chip; 2-Channel; 4-Signals)
Filter:    PCM: Standard/Minimum Phase digital (selectable)
                DSD: Standard/Extended Range analogue (selectable)
                DXD: Bit-Perfect Processing, analogue filter (fixed)
Input:    USB 2.0
                Compatible with iPhone, iPod, iPad and Android Devices USB-OTG
Output: SPDIF RCA (only PCM up to 192KHz)
                Audio RCA
                3.5mm Headphone
Dynamic Range: over 104dB
THD &N (35mW): Less than 0.005%
THD &N (Line): Less than 0.005%
Output Power (16R): over 130mW
Output Voltage: over 1.65V (over 100Ω)
Output Impedance (Zout): Less than 1Ω
Power Consumption: Less than 3W (charging battery and playback together)
Dimensions: 87(l) x 68(w) x 28(h) mm
Weight: 162g (0.43lbs)
 

iCAN nano
 

 
iCAN nano
Power Source: Battery / external 9V
Battery Life: ~70 Hours
Input:    RCA Stereo
                3.5mm
Output 6.3mm Headphone
                3.5mm adapter included
Analogue Processing / EQ: X-Bass, 3D Sound
Gain: 6dB/18dB (selectable)
Input Impedance: 100k
Output Impedance: Less than 1 ohm
SNR: 112dB(A)
THD &N (100mW): Less than 0.02%
Output Power (32R): 150mW (external power)
Dimensions: 87(l) x 68 (w) x 28 (h) mm
Weight: 160g (0.35lbs)
 
Accessories and Build Quality
Both gears come in pretty standard iFi while hard paper box, which we have seen on the micro line. With nano iDSD, you will get an RCA cable, an USB cable, a soft pouch, 4 rubber feet sticker and a pretty simple manual. With nano iCAN, you get the same RCA cable, soft pouch and rubber feet sticker, plus a 6.4mm-to-3.5mm adapter, 2 rubber bands, a small screw driver that is meant to help on pushing the gain switches, and a 9V iFi Ultra-Low-Noise power adapter. Two accessories that I wish iFi had included are a lower profile 6.4mm-to-3.5mm adapter and a short microUSB-to-USB-B OTG cable (*and I reckon a short USB-A-to-USB-B cable for the Apple foes). Both are actually not that easiest thing to find, but I was eventually able to source them from TaoBao myself. While the included 6.4mm-to-3.5mm adapter is fine by itself, it is really quite protruding with the 3.5mm plug from the headphone. I was able to find a lower profile version of the adapter that is 6mm lower. Well, every bit helps when you are traveling around.  As for the OTG cable, there simply isn’t that many places that you can find OTG cable for an USB-B socket.
 
Build quality is pretty much top notch for both the nano, which isn’t surprising as we have seen such level of quality on the micro series. LED indicator is located on the top, near the rear, with different color indicating different status. The shape of the housing is a bit awkward for a portable device, mainly due to the irregular shape of the front and back plate. The overall design of the nano series is pretty much like the micro series but half in length. Some of the elements that make perfect sense in the more desktop oriented micro series do look a little odd in a portable setting – such as RCA sockets, 6.4mm socket in nano iCAN and the USB-B socket in nano iDSD. I would think 3.5mm socket and micro USB might be more appropriate, as far as convenience is concerned, even though they are not that big of a deal. Beyond those, both nano are well designed and built.
 

iDSD nano
 

 
Battery Life
Nano iDSD can be run on both battery and USB power. If you switch it on before connecting to a PC or smart device, then it will run on pure battery power until the battery is flat. If you switch it on after connection, it will begin recharging. That makes it easier for the use with smartphone as many will reject USB DAC that draw too much power. The quoted battery life is about 10 hours on battery, which is pretty spot on from my own experience. For the most part, it will last around a day of normal usage before needing to recharge. That shouldn’t be a problem given most modern day smartphones probably won’t run much longer as well.
 
Nano iCAN on the other hand can run for a very long time before a recharge is required. The official number is around 70 hours. I haven’t actually drained the battery dry to test the battery life but it does seems to last like forever with a single charge. The only minor complaint I have with the nano iCAN is that it can only be recharged with the ULN adapter, which means you have to bring it with you on a long travel. The upside is that nano iCAN has more power when plugged in. So it is the case of win-some-lose-some.
 
 

iCAN nano
 

 

The gain switch on the bottom of nano iCAN
 
Gain, Hiss and EMI
The max voltage output on the nano iDSD is about 1.66V, pretty close to the 1.6V quoted in spec. It is not full 2V line level, but it should be plenty for portable use. From my observation, the RCA socket on the front is linked to the 3.5mm headphone socket and both are controlled by the volume knob, so the nano iDSD doesn’t really offer a line-out. According to iFi, the volume knob is actually a digital control over analog attenuation so you won’t lose any digital resolution by using it, yet it should offer near perfect channel balance at any volume. My measurement over the voltage output pretty much confirm that the channel balance is indeed perfect. They also point out that turning the volume to max essentially remove any analog attenuation and the signal should be at its best SNR, to approximate a line-level signal. Hiss is pretty good. Even with the hiss prone Shure SE530, I can’t hear any until the volume knob has passed around 2 o’clock, and that’s way too loud in normal listening with SE530. EMI is quite excellent on the nano iDSD as it remains in total silence right next to a smartphone when receiving call.
 
Nano iCAN offers two levels of gain, 6dB and 18dB. I’ll consider both being too high for IEM and sensitive headphone. You will probably want a low gain between 0~3 dB for IEM. As a result, hiss is quite noticeable with SE530 and I assume it will be the same for most of the sensitive IEM. EMI is also not particularly good as it is quite noticeable during call. That means the nano iCAN won’t be a good pairing with smartphone in general. Also, there is click and pop during startup and shutdown. Not very severe, but I’ll recommend unplugging headphone before startup / shutdown, especially if your headphone is quite sensitive. Unlike nano iDSD, the volume control in nano iCAN is fully analog, so there is some channel unbalanced coming from the volume pot when it is under 9 o’clock.
 

A comparison of the stock 6.4mm-to-3.5mm adapter (left) and the low profile adapter I found (right)
 
Sound Quality and EQ
As usual, I started my sound quality review on amp and DAC with an RMAA measurement. With nano iDSD, when measured under 16bit 48kHz PCM, you can clearly see the difference between the Standard and Minimum Phase filter used (selectable at the back of nano iDSD). Standard filter only has a tiny, inaudible -0.2dB roll off near 20kHz; with Minimum Phase filer however, it is a more noticeable -3dB @ 20kHz. If I am not mistaken, it is likely a Butterworth filter we have seen on many Hifiman players before. The filter selector switch also engages different filter during DSD and DXD playback as well, but I am not that interest in DSD/DXD so I won’t go into detail about them. Beside the effect of the filter, the rest of the frequency response is about as flat as it can be. With nano iCAN, the frequency response is also flat from 20Hz to 20kHz. The rest of the RMAA result has revealed no problem with either nano – noise, dynamic range, stereo crosstalk, etc are all fairly respectable. Per my measurement, output impedance for the nano iDSD and nano iCAN are both well below 1 ohm. Output current on the nano iDSD is low but adequate, but decently abundance on the nano iCAN. Overall, I didn’t find anything wrong during measurement.
 

The Standard filter vs Minimum Phase filter in nano iDSD.
 

iCAN with and without XBass enable
 
From my own personal experience - when it comes to USB DAC + amp, the common trend for most manufacturer is that they start with a good amp section first, then squeeze in a DAC that is just adequate for the job. Therefore many of them are more of an amp than they are a DAC. On the nano iDSD however, I’ll say you are getting a hell lot more of a DAC than an amp. If I am not mistaken, iFi is using the TI TPA6130A2 as nano iDSD’s headphone driver. It is a chip we had previously seen on FiiO E5 and E7. While it is not bad per se, it isn’t great either. It will drive your typical headphone well enough, but it doesn’t quite have the wow factor of a really good, full blown amp section. The good news is that nano iDSD does sound better than an E7, no doubt thanks to the far more mature DAC section, but you can still detect a sense of warmness that is typical to the TPA6130A2. Where nano iDSD really shine is when it is used as a source to feed into a better amp. Yes, technically you are double amping, but the result is well worth the effort. [update] According to iFi, technically TPA6130A2 only acts purely as the buffer stage of the DAC when the volume is turned to max, so it is not double amping per se. Another area that nano iDSD distinguishes itself is as an OTG devices for smartphone. While nano iDSD might not be the best sounding USB DAC there is, it is still far better than the built-in audio section of most smartphone out there. If you are using Android, with third party app like USB Audio Player PRO, you can even have full HD playback without a problem, PCM and DSD included.
 
One of the reason why I think nano iDSD is more of a DAC is how many features that iFi is able to pack inside. In the heart of nano iDSD sits one of TI’s top of the line DAC chip, the DSD1793. If you were to look up its datasheet, you will find it doesn’t support as much native DSD/DXD decoding as iFi has claimed. How did iFi do it then? Well, they were able to dig up some hidden features that are designed into the chip but not officially documented. Then they develop a custom XMOS solution to enable all those extra stuffs that you won’t find on any other DSD1793 implementation outside of iFi. The result is a sub$200 USB DAC that has features than usually belong to DAC that is priced in the thousands. As I have said, I am not that into DSD / DXD myself. But if you looking for a DAC that supports DSD / DXD in real native decoding, I don’t think you will find another USB DAC that does them all for such a price tag, especially one that also works well with smartphone..
 
So how about nano iCAN? From what I can tell, the basic amp topology seems to utilize an OPA1642 for gain stage, followed by MAX9722 as buffer. In between them, there are the Xbass and 3D Holographic Sound that I have nothing to say but praise for. As I have said on another review, MAX9722 can go from mediocre to really good, depends on the implementation. iFi has utilized it quite successfully on the micro iDAC, and the new implementation seems to work fairly well on the nano iCAN too. Subjectively speaking, nano iCAN doesn’t quite have the kind of maturity and effortlessness found on JDS Labs C5, but it has no problem matching up to FiiO E12. With E12, you get a sense of tighter control, power and intimacy. With nano iCAN, it is more neutral with better clarity and a really wide soundstage, even before the EQ is turned on. All and all, I won’t categorize nano iCAN as a top-tier portable amp in the sub-$200 price bucket, but it is definitely a very close runner-up.
 
The thing that really makes nano iCAN unique is however its XBass and especially the 3D Holographic Sound EQ. Sometime hardware EQ can be over implemented in portable amps, such as the case of C&C BH, where it helps a lot on some music but also ruins the whole image on others. The way iFi does its EQ is much gentler yet remains effective. They do exactly what they are meant to do without making anything sounds artificial or out of place. The degree of refinement is something I haven’t experienced on EQ from another brand of portable amp.
 

 

 

 
iPurifier
To explain it in a simple way, I guess you can say that iPurifier is a kind of EMI filter for USB transmission. I have tried it on my desktop setup, with both nano iDSD and micro iDAC, but doesn’t found it to make any noticeable difference. I do however find that it darken the background when pairing with my Xperia Z2 + nano iDSD a bit, though the effect is pretty subtle. Given it is meant to filter EMI, it makes sense as such since my desktop setup hasn’t really known to have suffer any EMI issue at all. I guess iPurifier is one of those devices that would really help if there is already a persistent case of EMI over the USB connection. Otherwise, you might be able to get away without one. It is more of a fine tuning tool rather than an instant improvement.
 
Just an extra note – iPurifier comes with an USB-B to mini USB adapter for the portable USB DAC, but I do hope it has an USB-B to micro USB adapter as well, since micro USB has become more and more dominant even among small USB DAC.
 

Size Comparison (from left): JDS Labs C5, FiiO E12DIY, nano iCAN, micro iCAN, nano iDSD, iPurifier.
 
Sum-up
I was thoroughly impressed by the micro series when they hit the market. While the nano series might not be quite the big smasher on performance as their elder siblings, they are themselves no sloth either. iFi Audio has managed to pack in some unique features to both nano iDSD and iCAN to make them stand out from the sea of portable amps and DAC in the market, while still makes sure they stay competitively priced. That’s no small feat on its own.
 
A thanks to iFi Audio for the samples.

[Impression] iFi nano iDSD and iCAN with a splash of iPurifer
iFi Audio has gained a great success over its Micro line of small sized desktop gears, and now it is pushing into the portable world with the Nano series. The nano iDSD is USB DAC that not only works with PC, but also has OTG support for the iDevice with OS7 (via camera connection kit / CCK) and Android that have USB Audio Class driver built-in (*for older Android that doesn’t have the driver, there is still a chance that USB Audio Player PRO will work). The nano iCAN on the other hand is a pure portable amp, but infused with the magical XBass and 3D Holographic Sound we have seen on the micro iCAN. Both are retailed under US$200.
 

 
Spec
 

iDSD nano
 

 
iDSD nano
Power Source: Battery/USB Bus power
                                DAC/Amp always run on battery
Battery Life: ~10 Hours playback*
Formats: 44.1/48/88.2/96/176.4/192/384kHz PCM
                2.8/3.1/5.6/6.2/11.2/12.4MHz DSD
                353/384kHz DXD
                Bit-Perfect DSD & DXD DAC by Burr Brown (1-DAC Chip; 2-Channel; 4-Signals)
Filter:    PCM: Standard/Minimum Phase digital (selectable)
                DSD: Standard/Extended Range analogue (selectable)
                DXD: Bit-Perfect Processing, analogue filter (fixed)
Input:    USB 2.0
                Compatible with iPhone, iPod, iPad and Android Devices USB-OTG
Output: SPDIF RCA (only PCM up to 192KHz)
                Audio RCA
                3.5mm Headphone
Dynamic Range: over 104dB
THD &N (35mW): Less than 0.005%
THD &N (Line): Less than 0.005%
Output Power (16R): over 130mW
Output Voltage: over 1.65V (over 100Ω)
Output Impedance (Zout): Less than 1Ω
Power Consumption: Less than 3W (charging battery and playback together)
Dimensions: 87(l) x 68(w) x 28(h) mm
Weight: 162g (0.43lbs)
 

iCAN nano
 

 
iCAN nano
Power Source: Battery / external 9V
Battery Life: ~70 Hours
Input:    RCA Stereo
                3.5mm
Output 6.3mm Headphone
                3.5mm adapter included
Analogue Processing / EQ: X-Bass, 3D Sound
Gain: 6dB/18dB (selectable)
Input Impedance: 100k
Output Impedance: Less than 1 ohm
SNR: 112dB(A)
THD &N (100mW): Less than 0.02%
Output Power (32R): 150mW (external power)
Dimensions: 87(l) x 68 (w) x 28 (h) mm
Weight: 160g (0.35lbs)
 
Accessories and Build Quality
Both gears come in pretty standard iFi while hard paper box, which we have seen on the micro line. With nano iDSD, you will get an RCA cable, an USB cable, a soft pouch, 4 rubber feet sticker and a pretty simple manual. With nano iCAN, you get the same RCA cable, soft pouch and rubber feet sticker, plus a 6.4mm-to-3.5mm adapter, 2 rubber bands, a small screw driver that is meant to help on pushing the gain switches, and a 9V iFi Ultra-Low-Noise power adapter. Two accessories that I wish iFi had included are a lower profile 6.4mm-to-3.5mm adapter and a short microUSB-to-USB-B OTG cable (*and I reckon a short USB-A-to-USB-B cable for the Apple foes). Both are actually not that easiest thing to find, but I was eventually able to source them from TaoBao myself. While the included 6.4mm-to-3.5mm adapter is fine by itself, it is really quite protruding with the 3.5mm plug from the headphone. I was able to find a lower profile version of the adapter that is 6mm lower. Well, every bit helps when you are traveling around.  As for the OTG cable, there simply isn’t that many places that you can find OTG cable for an USB-B socket.
 
Build quality is pretty much top notch for both the nano, which isn’t surprising as we have seen such level of quality on the micro series. LED indicator is located on the top, near the rear, with different color indicating different status. The shape of the housing is a bit awkward for a portable device, mainly due to the irregular shape of the front and back plate. The overall design of the nano series is pretty much like the micro series but half in length. Some of the elements that make perfect sense in the more desktop oriented micro series do look a little odd in a portable setting – such as RCA sockets, 6.4mm socket in nano iCAN and the USB-B socket in nano iDSD. I would think 3.5mm socket and micro USB might be more appropriate, as far as convenience is concerned, even though they are not that big of a deal. Beyond those, both nano are well designed and built.
 

iDSD nano
 

 
Battery Life
Nano iDSD can be run on both battery and USB power. If you switch it on before connecting to a PC or smart device, then it will run on pure battery power until the battery is flat. If you switch it on after connection, it will begin recharging. That makes it easier for the use with smartphone as many will reject USB DAC that draw too much power. The quoted battery life is about 10 hours on battery, which is pretty spot on from my own experience. For the most part, it will last around a day of normal usage before needing to recharge. That shouldn’t be a problem given most modern day smartphones probably won’t run much longer as well.
 
Nano iCAN on the other hand can run for a very long time before a recharge is required. The official number is around 70 hours. I haven’t actually drained the battery dry to test the battery life but it does seems to last like forever with a single charge. The only minor complaint I have with the nano iCAN is that it can only be recharged with the ULN adapter, which means you have to bring it with you on a long travel. The upside is that nano iCAN has more power when plugged in. So it is the case of win-some-lose-some.
 
 

iCAN nano
 

 

The gain switch on the bottom of nano iCAN
 
Gain, Hiss and EMI
The max voltage output on the nano iDSD is about 1.66V, pretty close to the 1.6V quoted in spec. It is not full 2V line level, but it should be plenty for portable use. From my observation, the RCA socket on the front is linked to the 3.5mm headphone socket and both are controlled by the volume knob, so the nano iDSD doesn’t really offer a line-out. According to iFi, the volume knob is actually a digital control over analog attenuation so you won’t lose any digital resolution by using it, yet it should offer near perfect channel balance at any volume. My measurement over the voltage output pretty much confirm that the channel balance is indeed perfect. They also point out that turning the volume to max essentially remove any analog attenuation and the signal should be at its best SNR, to approximate a line-level signal. Hiss is pretty good. Even with the hiss prone Shure SE530, I can’t hear any until the volume knob has passed around 2 o’clock, and that’s way too loud in normal listening with SE530. EMI is quite excellent on the nano iDSD as it remains in total silence right next to a smartphone when receiving call.
 
Nano iCAN offers two levels of gain, 6dB and 18dB. I’ll consider both being too high for IEM and sensitive headphone. You will probably want a low gain between 0~3 dB for IEM. As a result, hiss is quite noticeable with SE530 and I assume it will be the same for most of the sensitive IEM. EMI is also not particularly good as it is quite noticeable during call. That means the nano iCAN won’t be a good pairing with smartphone in general. Also, there is click and pop during startup and shutdown. Not very severe, but I’ll recommend unplugging headphone before startup / shutdown, especially if your headphone is quite sensitive. Unlike nano iDSD, the volume control in nano iCAN is fully analog, so there is some channel unbalanced coming from the volume pot when it is under 9 o’clock.
 

A comparison of the stock 6.4mm-to-3.5mm adapter (left) and the low profile adapter I found (right)
 
Sound Quality and EQ
As usual, I started my sound quality review on amp and DAC with an RMAA measurement. With nano iDSD, when measured under 16bit 48kHz PCM, you can clearly see the difference between the Standard and Minimum Phase filter used (selectable at the back of nano iDSD). Standard filter only has a tiny, inaudible -0.2dB roll off near 20kHz; with Minimum Phase filer however, it is a more noticeable -3dB @ 20kHz. If I am not mistaken, it is likely a Butterworth filter we have seen on many Hifiman players before. The filter selector switch also engages different filter during DSD and DXD playback as well, but I am not that interest in DSD/DXD so I won’t go into detail about them. Beside the effect of the filter, the rest of the frequency response is about as flat as it can be. With nano iCAN, the frequency response is also flat from 20Hz to 20kHz. The rest of the RMAA result has revealed no problem with either nano – noise, dynamic range, stereo crosstalk, etc are all fairly respectable. Per my measurement, output impedance for the nano iDSD and nano iCAN are both well below 1 ohm. Output current on the nano iDSD is low but adequate, but decently abundance on the nano iCAN. Overall, I didn’t find anything wrong during measurement.
 

The Standard filter vs Minimum Phase filter in nano iDSD.
 

iCAN with and without XBass enable
 
From my own personal experience - when it comes to USB DAC + amp, the common trend for most manufacturer is that they start with a good amp section first, then squeeze in a DAC that is just adequate for the job. Therefore many of them are more of an amp than they are a DAC. On the nano iDSD however, I’ll say you are getting a hell lot more of a DAC than an amp. If I am not mistaken, iFi is using the TI TPA6130A2 as nano iDSD’s headphone driver. It is a chip we had previously seen on FiiO E5 and E7. While it is not bad per se, it isn’t great either. It will drive your typical headphone well enough, but it doesn’t quite have the wow factor of a really good, full blown amp section. The good news is that nano iDSD does sound better than an E7, no doubt thanks to the far more mature DAC section, but you can still detect a sense of warmness that is typical to the TPA6130A2. Where nano iDSD really shine is when it is used as a source to feed into a better amp. Yes, technically you are double amping, but the result is well worth the effort [update] According to iFi, technically TPA6130A2 only acts purely as the buffer stage of the DAC when the volume is turned to max, so it is not double amping per se. Another area that nano iDSD distinguishes itself is as an OTG devices for smartphone. While nano iDSD might not be the best sounding USB DAC there is, it is still far better than the built-in audio section of most smartphone out there. If you are using Android, with third party app like USB Audio Player PRO, you can even have full HD playback without a problem, PCM and DSD included.
 
One of the reason why I think nano iDSD is more of a DAC is how many features that iFi is able to pack inside. In the heart of nano iDSD sits one of TI’s top of the line DAC chip, the DSD1793. If you were to look up its datasheet, you will find it doesn’t support as much native DSD/DXD decoding as iFi has claimed. How did iFi do it then? Well, they were able to dig up some hidden features that are designed into the chip but not officially documented. Then they develop a custom XMOS solution to enable all those extra stuffs that you won’t find on any other DSD1793 implementation outside of iFi. The result is a sub$200 USB DAC that has features than usually belong to DAC that is priced in the thousands. As I have said, I am not that into DSD / DXD myself. But if you looking for a DAC that supports DSD / DXD in real native decoding, I don’t think you will find another USB DAC that does them all for such a price tag, especially one that also works well with smartphone..
 
So how about nano iCAN? From what I can tell, the basic amp topology seems to utilize an OPA1642 for gain stage, followed by MAX9722 as buffer. In between them, there are the Xbass and 3D Holographic Sound that I have nothing to say but praise for. As I have said on another review, MAX9722 can go from mediocre to really good, depends on the implementation. iFi has utilized it quite successfully on the micro iDAC, and the new implementation seems to work fairly well on the nano iCAN too. Subjectively speaking, nano iCAN doesn’t quite have the kind of maturity and effortlessness found on JDS Labs C5, but it has no problem matching up to FiiO E12. With E12, you get a sense of tighter control, power and intimacy. With nano iCAN, it is more neutral with better clarity and a really wide soundstage, even before the EQ is turned on. All and all, I won’t categorize nano iCAN as a top-tier portable amp in the sub-$200 price bucket, but it is definitely a very close runner-up.
 
The thing that really makes nano iCAN unique is however its XBass and especially the 3D Holographic Sound EQ. Sometime hardware EQ can be over implemented in portable amps, such as the case of C&C BH, where it helps a lot on some music but also ruins the whole image on others. The way iFi does its EQ is much gentler yet remains effective. They do exactly what they are meant to do without making anything sounds artificial or out of place. The degree of refinement is something I haven’t experienced on EQ from another brand of portable amp.
 

 

 

 
iPurifier
To explain it in a simple way, I guess you can say that iPurifier is a kind of EMI filter for USB transmission. I have tried it on my desktop setup, with both nano iDSD and micro iDAC, but doesn’t found it to make any noticeable difference. I do however find that it darken the background when pairing with my Xperia Z2 + nano iDSD a bit, though the effect is pretty subtle. Given it is meant to filter EMI, it makes sense as such since my desktop setup hasn’t really known to have suffer any EMI issue at all. I guess iPurifier is one of those devices that would really help if there is already a persistent case of EMI over the USB connection. Otherwise, you might be able to get away without one. It is more of a fine tuning tool rather than an instant improvement.
 
Just an extra note – iPurifier comes with an USB-B to mini USB adapter for the portable USB DAC, but I do hope it has an USB-B to micro USB adapter as well, since micro USB has become more and more dominant even among small USB DAC.
 
[update 2] Upon reading about the comment above, iFi has decided to included the micro USB adapter into the iPurifier package in the future.
 

Size Comparison (from left): JDS Labs C5, FiiO E12DIY, nano iCAN, micro iCAN, nano iDSD, iPurifier.
 
Sum-up
I was thoroughly impressed by the micro series when they hit the market. While the nano series might not be quite the big smasher on performance as their elder siblings, they are themselves no sloth either. iFi Audio has managed to pack in some unique features to both nano iDSD and iCAN to make them stand out from the sea of portable amps and DAC in the market, while still makes sure they stay competitively priced. That’s no small feat on its own.
 
A thanks to iFi Audio for the samples.

With desktop PC sale declining and mobile devices on the rise, thumb drive sized USB DAC has become the quick fix for poor sound quality that is all too common in portable computer and smart devices. Creative’s answer to that demand is the new Sound Blaster E1 – a multipurpose USB DAC + headphone amp + mic that boosted with quite a few impressive features.
 

 
Spec
SBX Pro Studio: Supported
CrystalVoice: Supported
Scout Mode: Supported
Max. Playback Quality: 24-bit / 44.1kHz (Stereo)
Max. Recording Quality: 16-bit / 44.1kHz
Output: Stereo
Battery Life: Up to 25 hours
SNR: 106dB
Headphone Out: 1 x 3.5mm jack
Headphone Out / Mic In: 1 x 3.5mm jack
Line In:  1 x 3.5mm jack (4-pole)
Headphone Amp: Up to 600 Ohms
Microphone Type: Built-in mono microphone
Dimensions: 35 x 19 x 66 mm (1.37 x 0.74 x 2.59 inches)
Weight: 25 grams
MSRP: USD$50
 

 

 
Packaging, Accessories and Build Quality
E1 comes with a fairly typical paper box, well printed but nothing fancy. Besides the manual, the only two accessories are a USB cable and a 3.5mm TRRS-to-TRRS interconnecting cable that is roughly 85cm in length. One of the feature on the E1 is that it can act as a headphone amp for smartphone, where it has a single button remote to play / pause music or pick up call and the built-in mic that will serve as the mic for hand-free calling. In order to support those functions, obviously you will need to use the TRRS cable to connect the E1 to your smartphone.
 
Build quality is solid, if not a bit unremarkable. The whole device is made out of plastic though the overall finishing is decent. There is a shirt chip integrated on the back, making it looks a little like a slightly oversized Bluetooth headset unit. The only minor complaint I have is that I wish the volume slider can be a bit recessed just so it will minimize any chance of accidental volume adjustment. However, the volume slider does have some resistant built into it so it is not like it will just slide with minimum force.
 

 
Gain, Hiss and Battery Life
As a USB DAC+amp, the max output is about 1.93V. As a pure headphone amp, E1 has a gain of 6dB. It can actually pump out higher volume as a pure headphone amp than as a USB DAC+amp, probably due to the limited volume coming out of the DAC section. That means that although Creative claims that the E1 can drive headphone up 600ohm, you might not get enough volume if the headphone sensitivity isn’t high enough. That is however still fairly reasonable consider the compact size of E1. It is of course not actually going to replace a full blown headphone amp anytime soon, but it should be more enough for the majority of headphones in the market that are barely over 32 ohm.
 
One feature that I particularly like about the E1 is its dual headphone-out. Now such implementation is actually nothing new but the cool thing about it is that the two headphone-out are independently driven by two headphone driver chips, the Maxim MAX97220 if I am not mistaken. That means connecting two headphones will not degrade the sound quality, as opposed to having them driven in parallel by just one chip.
 
Hiss performance is excellent on the E1 as I heard nothing even with the very hiss prone SE530. There is no click and pop noise during start up as well, which is also excellent.
 
Battery life is officially quoted at 25hours (as a pure headphone amp as I imagined, since it will be powered by USB port when it is used as USB DAC+amp). I never quite drained it dry to confirm the number, but it does seems to run very long without needing a recharge. In fact, I was still running off the initial charge after playing with it on and off for the first week. With the current fast rate of battery drainage on most smartphone, I’ll say there is a good chance the E1 will outlast your smartphone on most day easily.
 

 
Sound Quality
As with most of my review on headphone amp and DAC, I started with a basic RMAA measurement. The result is mostly clean and without any noticeable issue. Frequency response is pretty much flat from 80Hz to 20kHz, with a less than -1dB roll off at 20Hz that should be near inaudible to most people. There is however a minor imbalance between the two channels, which I assume is likely caused by the volume slider in my review unit. It is however small enough that I never notice it during listening but only after the measurement. Output impedance is measured and calculated to be around 2~2.5ohm for both headphone-out, which is quite decent. Current output is okay for the most part. I’ll have like a bit more but it should be enough except for the very low impedance load.
 

 
Subjectively, the E1’s sound is in the warm side when used as a standalone portable amp, with good texture and sweetness though a bit smooth and lack a good sense of air and depth. It is actually quite similar to FiiO E07K (which also uses the same headphone driver chip), but less grand on overall image. I’ll say for the most part the overall SQ is about the same level as FiiO E6, which is not bad at all for what is meant to be entry level gear. As an USD DAC however, the E1 opens up more. It still has a sense of warmth in its presentation, but more revealing and definitely better in the rendering of space. No doubt it benefits from Creative’s software bundle, enhancing the soundstage and detail while not being artificial sounding (*there are also a few EQ and gaming setting that should appeal to those who are more centred on movie and PC game). While it isn’t exactly audiophile’s sound quality, I don’t think anyone can expect more for its price tag
 

 
Extra
Here are some of the features that don’t quite fit into the rest of the review but they are worth noting nonetheless.

• Though E1 only supports sampling rate up to 48kHz (*no HD there!), it does support bitdepth of 24bit. This means adjusting digital volume on your PC should not degrade the resolution of your music, if you decided to do so.
• One of the headphone-out can double as mic-in when it is in USB DAC mode. I assume this is designed for gaming headset which usually comes with two 3.5mm jack (one for sound and one for mic). You will however need to enable it within the Sound Blaster software setting.

 

Size comparison (from left): Apple iPod Nano 7G, E1, digiZoid ZO2.
 
Sum-up
What sets E1 apart is really its unique set of features. Creative has managed to pack just about everything you want for an basic external PC soundcard for headphone into a really small body, while making it double as a standalone amp and still keeping it cheap yet competent. It is the stick of all trade and a relevant gadget that fits right into this post PC era.
 
A thank to Creative for the sample.

The Korean company really needs no introduction at this point. They have proven themselves as a capable IEM maker with a series of top of the line hybrid as well as some good sound yet budget friendly dynamic IEM. The new Altone 200 is the continuation of the company’s hybrid line of IEM, with a never-heard-of price point nonetheless. The best part? You are not getting lesser of SQ just because you are paying a cheap price.
 

 
Spec
Driver Units: Knowles' TWFK Double Balanced Armature + 8.0mm Single Dynamic Unit
Impedance: 22 ohm @ 1 kHz
Sensitivity: 105 dB @ 1 kHz
Power: 100 mW (Max)
Frequency Response: 20 Hz ~ 20 kHz
Connector: 3.5 mm / 24 K Gold coated L-Type Plug
Cord: PVC Round 1.2 M / Y-Type
Weight: 24 g
MSRP: USD$145 + USD$20 EMS Shipping
 

 
Packaging, Accessories and Build Quality
Since you are not getting lesser of a SQ, something else will have to give. In this case, the packaging is definitely not quite matching what the IEM can do. Same can be said to the accessories department as well. All you’ll get are the fairly basic silicone eartips of various size, a soft case, a pair of foam and a shirt clip. Not nearly as elaborate as the previous top model we have seen from T-PEOS, but I won’t really complain at this kind of price. The overall design is also simplified, where the removable cable design is, well, removed. But the overall build quality is still very solid, considered that the housing is still mainly made out of stainless steel like much of T-PEOS’s line-up. The good thing about the simplified design is that the earpieces are probably one of the smallest among all triple driver hybrid IEM, which is definitely not a bad thing comfort wise.
 

 
Sound Quality
The sound signature of Altone 200 is warm and slightly sweet with very mild U-shaped frequency response. Bass reaches down deep, with just a small touch of rumble and quantity enough for most except for the most hardcore of basshead. Mid range is just a tab recessed compared to bass, though still retains quite a good amount of sweetness and texture while at the same time places the vocal just far enough to give good spaciousness but not enough to distance it from the listener. Treble reaches up quite well, but the upper extension is just a tab smooth and some of the top-end sparkle is missing. However, it still retains enough detail that you will almost never notice any missing of detail unless you are just switching from a bright and analytical set of headphone. Soundstage is fair. If its older brother the H-200 has a 3^rd row seat in a theatre, I reckon Altone 200 is more like a 2^nd row seat. It is not right in the face but you can certainly still feel the intimacy.
 
For the most part, the new Altone 200 is different from the older model (i.e. H-100 and H-200) in the sense that it exhibits the least ‘grand and open’ of a presentation, but not in a bad way. It is more upfront and intimate, and you probably won’t notice it as a 3 ways hybrid if you were not told. Those who don’t like the T-PEOS’ more V-shaped and opened sound in the past will more likely going to find Altone 200 enjoyable while those who do like the old sound signature shouldn’t feel abandoned either. While Altone 200 does have a more versatile sound signature that should better suited for different listening style and genre of music, the difference however doesn’t make Altone 200 a vastly better or worst sounding IEM when compared to the older flagship H-200. As with most IEM of this high calibre, you are really just looking (or listening, to be more precise) for the minute difference in presentation and how it fits to your taste rather than flaws in pure technical sense. It is more of an evolution of tuning, as opposed to a revolution of sound quality.
 

 
Sum-up
T-PEOS has made top quality IEM in the past, and continues so with the new Altone 200 – no surprise there. The true smasher here is however on the price. With a fraction of its competitors’ price, you are getting a tremendous amount of bang-for-the-bucks with an IEM that can compete in the top-tiers’ category. That’s, in every sense of the word, budget Hi-Fi at its best.
 
A thanks to T-PEOS for the review sample.

The Korea based T-PEOS surprised the IEM world with their hybrid IEM a few years ago and still continues to push for more innovative design. The RICH200 is meant to be a step up from the company’s first dynamic model D-200, but keeping the same high value-for-money factor.



Spec




Transducer: 8mm Dynamic
Power: 3mW / 30mW (normal / max)
Impedance: 32 ohm @ 1kHz
Sensitivity: 102dB @ 1kHz
Frequency Response: 20Hz ~ 15kHz
Cable: 1.2m Half-Flat with single button + mic
Connector: 3.5mm L-shaped TRRS 24K Gold Plated Plug
MSRP: US$28

Packaging, Accessories and Build Quality
Nothing spectacular about the packaging , but nothing to really complain about either. As you might have expected, there isn’t much about to talk about accessories wise on the cheaper RICH200, which includes just the various size eartips and a shirt clip. The models come with single button remote + mic so it should work with most smartphone out there.






Like the previous reviewed T-PEOS models, the models is quite well built and nothing to complain about. Overall, the Korean seems to play a little more attention to detail than most of the Chinese brands. RICH200 does come with flat cable, but it is the slim type so it shouldn’t annoy those of you who dislike flat cable.

Sound Quality


RICH200 has a sound signature that warm and sweet, but specious and tilting toward neutral. Bass has good reach and quite snappy, but quantitatively only slightly above neutral. Mid is well blended, a little further away with good space, but doesn’t sound overly distanced or lacking texture. Treble too has good reach and clarity, though missing some of the top-end sparkle. It is actually quite well balanced between being too dull and too sharp, giving a sense of smoothness yet still presenting most of the micro-detail. Soundstage is quite good with fairly wide image and decent depth. To put it short, RICH200 has a very similar presentation to T-PEOS’s own D-200 series, but with a wider soundstage and not quite as warm, making it a more versatile sound that should go well with all kind of music and not just the mainstream that D-200 is more suitable to. Overall, it is a small but noticeable step-up.

Sum-up
T-PEOS, the company that once surprised the IEM community continues to solidify its status as a strong player in the market, offering seriously good products at a great price point. While RICH200 doesn’t really get as much spotlight as the company top-end models, It is nonetheless great buy on its own right. If that’s any indication, I guess we can expect many more goodies from the Korean for years to come.

Big thanks to T-PEOS and Mellow Work Studio for the samples.

The Korea based T-PEOS surprised the IEM world with their hybrid IEM a few years ago and still continues to push for more innovative design. As the name suggested, the H-100J is related to T-PEOS’s original flagship hybrid, the T-100. However, the T-100J isn’t meant to be a continuance but rather a rebalance, in order to appeal to those who do not like the V-shaped sound of the original T-100.



Spec




Transducer: 1 BA + 1 Dynamic Dual Driver Hybrid
Power: 3mW / 20mW (normal / max)
Impedance: 30 ohm @ 1kHz
Sensitivity: 102dB @ 1kHz
Frequency Response: 20Hz ~ 10kHz
Cable: 1.2m with single button + mic
Connector: 3.5mm L-shaped TRRS 24K Gold Plated Plug
MSRP: US$98

Packaging, Accessories and Build Quality
Nothing spectacular about the packaging, especially compared to the luxurious H-100, but nothing to really complain about either. The H-100J comes with soft pouch, over-the-ear guide, shirt clip, different sized eartips, one pair of form tips, as well as a short TRRS-to-TRS cable adapter, just in case your DAP or amp doesn’t take TRRS plug. The cable comes with single button remote + mic so it should work with most smartphone out there.






Like the previous reviewed T-PEOS models, H-100J is quite well built and nothing to complain about. There is a tiny bit of driver flex but very minor and shouldn’t be a problem at all. Overall, the Korean seems to play a little more attention to detail than most of the Chinese brands.

Sound Quality



H-100J has a classic warm and sweet sound that is smooth and full overall. Like the original H-100, bass reaches down deep and is abundance. Not bass monster level but more than enough for most except the most hardcore of basshead. Mid is full and very well textured, making vocal quite a treat. Treble is mostly smooth and has a slight roll off near the top, missing most of the sparkle and some of the micro-detail. Lower treble can get slightly grainy on bright music as well, though not always the case. Due to the forward and room filling presentation, soundstage is only average, neither wide nor closed-in. There is really nothing similar between the H-100 and the H-100J beside perhaps a good strong bass. H-100J, which is intended to ‘cure’ the issue for those who find the original sound too V-shaped and lacking mid texture, is definitely achieved its goal. By swapping out the micro-detail oriented driver to the more mid centric SR driver, T-PEOS has managed to reinvent the sound for the H-100 series. But it isn’t really an upgrade per se, more of a trade-off between technicality and musicality. So instead of being more suitable for instrument and Classical like the original H-100, the new H-100J plays more nicely with mainstream Pop, Rock and any vocal based genre.


From left: H-100J, H-100, H-200.

Sum-up
T-PEOS, the company that once surprised the IEM community continues to solidify its status as a strong player in the market, offering seriously good product at a great price point. While the H-100J doesn’t really get as much spotlight as the company top-end models, it is nonetheless great buy on its own right. If that’s any indication, I guess we can expect many more goodies from the Korean for years to come.
 
Big thanks to T-PEOS and Mellow Work Studio for the samples.

[Impression] miniwatt n4
The Hong Kong based company miniwatt has quite an interesting history as they have the tendency to focus on one product at a time. I actually won their first product a few years ago in a contest, and it was the tiny tube based speaker amp called S1. The n4 under review here however has nothing to do with tube anymore, but a DAC + headphone-amp aiming toward the PC audiophiles.
 

 
Spec
USB 2.0 Async Mode (driver required) supports up to 32bits/192k (upsampling)
DAC: PCM1795
DAC Filter and Headphone Driver: LM4562 with independent L and R channel circuit at output stage
Headphone Output: 100mW at 32Ohm
Line Output: 1.8V rms (auto mute when using headphone out)
USB 2.0 audio to S/PDIF converter, 32/192k SPDIF output
Digital Attenuation: 0 dB to –120 dB, 0.5db/Step
USB-powered, no external power supply required
Dimensions: 115mm (L) x 74mm (W) x 20mm (H)
Finish: CNC Silver Powder Coated Aluminium Panel with Laser Etching + Stitched Leather Extrusion
 

 
Packaging, Accessories and Build Quality
N4 comes with pretty much minimum packaging. As far as accessories goes, only a USB cable – which is fine for what it is. However, I wish miniwatt has included some kind of a quick start guide inside, or at least a piece of paper pointing to their website. While the n4 is pretty easy to setup, it does require a driver to run in Windows, and you can only get it from miniwatt’s website (which isn’t the easiest the find: miniwatt.com.hk)
 
The build quality is pretty good and rather unique in design. You have the 3.5mm headphone-out and volume control on the front; the USB input, RCA line-out and coax digital out on the back. The housing is aluminium but wrapped in PU leather, offering a nice exterior finishing.
 

You can see the stitches on the side.
 
SQ
Let’s talk about the hardware first. On paper, the n4 pretty much has all the goody you will want from a USB DAC of its price bucket – asynchronous USB mode, top-end TI’s DAC chip that will upsample everything to 32/192, a fairly powerful headphone driver based on the well regarded LM4562, pretty high line output, digital-out as well as digital volume control. So do these translate to actual performance? RMAA measurement on the headphone-out shows flat 20Hz to 20kHz frequency response, slightly higher Intermodulation distortion but nothing alerting, and otherwise very clean output. Max headphone-out is the same as line-out, at around 1.7Vrms. Output impedance is calculated to be well under 1 ohm. Output current is decent as well, not particularly high but should be quite enough even for low impedance IEM. Overall, everything seems to stand up to my basic measurement. But the one thing I do want to complain about is the digital volume control mechanism – on Windows 8.1 where you have 0 (mute) to 100 (max), the first few steps on the volume control simply are too loud. RE0, for an example, can only be listened at around volume 6~8, and it is worst for more sensitive IEM. Some of my IEM can’t even be listened at volume 1. I have to lower both the volume on the playback software as well as the Windows master volume control so I can have some finer control over the range. This is kind of far from the “0 dB to –120 dB, 0.5db/Step” quoted in the spec. The good news is that hiss is actually quite low even with sensitive IEM, but you probably won’t use such sensitive an IEM given the volume issue and therefore it is unlikely you are going to enjoy the benefit of the low hiss. Given the volume is fully digital, the line-out is also affected. To get the best out of it, you will want to max it out on the Windows setting when you are using n4 as a source to feed an amp.
 

 

 
So how does the n4 sound subjectively? On the line-out alone, it is pretty much what you can expect from what I’ll consider fairly classic TI’s top DAC will sound like – overall neutral with a sense of warmth and organic. Compared to the crisp and clean sounding ES9023 in the iFi Audio’s iDAC, the PCM1795 in n4 is smoother and not as revealing on the top, but carries a little bit more texture on the bass and mid. It might seems like a lot of difference on how I described them, but the truth is the difference between them is fairly subtle. You might not notice much if you don’t have some very revealing headphone in the first place. Simply put, iDAC would have more of a wow factor in first listening while n4 is more musical in the long run. Both are quite excellent on their own right.
 
So how is the headphone-out then? Well, it is definitely not quite as good as a standalone JDS labs O2, but still edges out just a bit over the headphone-out of iDAC. Compared to iDAC, n4’s headphone’s presentation is similar but grander - with wider soundstage and deeper reach into the bass region. It is fairly clean and neutral, if not just a little on the leaner side of things and kind of compensating the slight warmth from the DAC section. As mentioned before, my only complaint is the volume simply being too loud for sensitive headphone and IEM in my Windows 8.1 machine. I am not sure if it is the same for other Windows PC, but it is something miniwatt needs to look into.
 

Size comparison (from left): Leckerton Audio UHA-4, n4, FiiO E18.
 
Sum up
Despite the volume control issue, the n4 is a fairly well rounded bit of kit – it is well made, decent in design, and good in performance. The original price of almost $350 is however on the high side, consider you can get an O2+ODAC or iFi Audio iDAC for under $300 and both offer compatible performance. But the price has been lowered since early 2014 to $199 (directly from miniwatt's webstore), making the n4 much more attractive and easier to recommend. If miniwatt can take care of the volume issue, n4 will have no problem being one of the front runner of its class.
 
A thanks to miniwatt for the sample.

When it comes to Edifier, they are best known for their desktop PC speaker range and acquiring the prestigious electrostatic headphone company Stax. But just because they now own Stax doesn’t mean they are going to negate their own headphone production line. The current top-of-the-line H850 can be found online for just under US$60. Okay, maybe not quite the Stax level of headphone solely judging by the price, it still swings out quite a heavy punch in the feather weight class.





Spec
Rated Power: 50mW
Frequency Response: 20Hz~20kHz
SPL: 96dB
Impedance: 32ohm
Cable Length: 2M





Accessories and Build Quality
The packaging is fairly plain, with the only included accessory being a 3.5mm to 6.4mm adapter. For the price, I guess it is hard to fault Edifier. But I do really hope there is an extra set of short cable. The included 2M cable, while decent, is a bit too long for outdoor. The cable has a removable, lock-in 3.5mm plug design to the left earcup but due to the lock-in mechanism, it is unlikely you will ever find a suitable shorter cable.

The overall build quality is quite good, but the design is a little bland. It looks just like most other generic headphones. The headphone itself is pretty light and overall quite comfortable for long hour usage. Not much to really complain nor praise about.





Sound Quality
The H850 is tuned by Phil Jones of Phil Jones Pure Sound and founder of Acoustic Energy (plus a few other well-known speaker companies too). In fact, Phil Jones has been working with Edifier on several speaker products so far and even offered H850 rebadged and sold as part of Pure Sound’s line-up for bass guitarist. That kind of makes sense as H850 does quite well with string instrument, especially when it comes to micro-detail reproduction.

To put it short, H850 is a bit on the lean and clean side of things. It is mostly neutral with a hint of brightness on the top. Bass extends well, only missing the very deep end just under 30Hz. Quantitatively it is closer to neutral so bassheads need not apply. Mid is clean as well, neither too sweet nor too dull. Lower treble can be a little sharp at time, almost borderline sibilant if you push the volume too high. Higher extension on the other hand is quite excellent, with a good amount of sparkle no less. Soundstage is quite good, better on the width than depth. Consider the price point, H850 has surprising very few flaw in its overall presentation. If I have to pick one thing – it will be that H850 can be just a little too lean at time. But it is curable if you give it just a little bit of bass boost. A mere +3dB into sub-bass is enough to inject the missing texture back into the mix and makes H850 sounds much more musical. While H850's sensitivity is a little on the lower side, it doesn’t need extra amount of power. A warmish amp with bass boost will however work wonder. JDS Labs C5, FiiO E12 and especially digiZoid ZO2 go really well with H850. But if you are really into a more neutral presentation, H850 is already good at it is.



Sum up
With a street price just under US$60, H850 is an excellent bargain. While it is not exactly Stax, I can still see it competing easily with headphone that doubles its price. It is an excellent effort from Edifier and well worth recommended for those with a tight budget in mind. As I was searching around, I even found a local deal for just US$30 – that’s pretty much a steal! Do check your local dealer as you might be able to pick one up on the cheap.

A thank to Edifier Malaysia / Inter-Asia for the sample.

Early in the year, I reviewed the Lear LCM-5. Though it is excellent sounding, the stock cable does look a little dull. At the time, Lear already announced they will release an upgrade cable for those who want to complete the whole package of sound and look. It has been released a few months ago and it is called the C2. Oh, it is actually quite affordable too.



The wire inside the new cable is actually similar to the stock wire, made out of high purity silver plated OFC. However, there is where the similarity ends. First of all, the new cable has a much better finishing than the old cable. It is made in Tinsel wire fashion to ensure better flexibility as well as durability. So even though it has thicker diameter, it is still softer than the stock cable. The pins connector as well as the 3.5mm plug also look more premier. The new cable comes in two flavors:  a normal black version that costs US$60 and a better looking transparent version with US$5 more. To ensure the transparent cable won't suffer the 'oxidation green' effect like most other transparent cable, the wire inside has been treated with an extra layer of anti-oxidation coating which hopefully will keep the cable into best looking condition for years to come.


C2 on the left, Apollo on the right.



I have been using Effect Audio Apollo cable with the LCM-5 for a while now and I am quite satisfied with the pairing. Now I am just as happy with the C2, as it matches the Apollo for build quality and it looks even better. Yes, the C2 doesn't offer a better sound per se, but there is not reason why you won't want your custom IEM to look as good as it can for a mere $65.

Though the C2 has been released, it is not listed on Lear's website yet. You can send them an email for inquiry or mention it when ordering your custom IEM from them. They also accept build-to-order C2 with different connector so you can use it on other IEM as well (*which probably going to cost a bit more). Again, no reason to save $65 when you already spent much more money on your custom. The new C2 is well worth the extra cash.

I have reviewed the Fireye Mini from FireStone Audio a while ago and now an updated version has come out. The Mini+ keeps to the ultra-portable size while adding in a few more very useful features and mending some of its predecessor’s shortcomings.



Spec
Amplifier Structure: Class-AB, coupling capacitor-less.
Power Structure: Built in battery power supply
Headphone Impedance: 32 ohm to 600 ohm
Bass Boost: Switchable, +3dB @ 130Hz
Circuit Protect: Output short circuit / temperature protect
Usage Time: With 100% full battery around 12hrs.
Charging Method: Using PC or USB adapter to charge
Charging Time: Fully charging in 1.5hrs, fast charging in 1hrs (90%)
Main Opamp: Maxim MAX9722A
Audio Performance
Frequency Response (From 40Hz to 15kHz): +0.03dB ~ -0.04dB
Noise level: -109.2dB
Dynamic range: 109dB
THD%: 0.0003%
Stereo Crosstalk: -98.5dB
MSRP: ~US$60





Accessories and Build Quality
Compared to the original Mini, the Mini+ comes really well packed - and since this seems to be a joint project with the Taiwan based performing art group ‘Chio Tian’ (= ‘9 Sky’), it also take on a very Chinese traditional + fusion styling. The removable aluminum face plate has the ‘9 Sky’ dragon logo and there are some stickers with Chinese opera facial printing. For actual accessories, you’ll get the USB charging cable as well as a TRRS interconnecting cable.

As always, FireStone has maintained a good level of build quality. While it might not be functionally useful, the face plate does add a sense of class and uniqueness onto the little amp. It is so well made that, even though it does not have not any clamping nor double taped on the inside, it stays on the amp and never once falls out by its own. The amp itself has no power switch and instead turns on automatically once the headphone-out is plugged in (and power down vice versa). The only switch on the amp is for the bass boost. Size wise, the Mini+ is about 60% larger than the original Mini. Still it is fairly small, about the same footprint as FiiO E6 but 2mm thicker and well within the realm of ultra-portable.

A big plus on the Mini+ is that it supports mic + remote pass-through. This means you can still receive call with a headset on the Mini+ when it is paired with cellphone, or control volume with a headset’s remote with Mini+ on an iDevice. That’s a very handy function to have.





Gain, Hiss and EMI
Mini+ has a fairly modest fixed gain of +6dB, which is the same as the Mini. If you hear any hiss on the Mini+, a good chance is that it is coming from the source as Mini+ is pretty much hiss free on its own but has the tendency to pick up hiss from the source. For example, my Xepria TX is kind of hissy with the Mini+ while Nano 7G is fairly quiet. To avoid hiss, the best thing to do is probably not to use hiss prone IEM, given you might not have a choice on the source. There is some mild EMI with the Mini+, but not enough to be a major concern.

Battery Life
This is where Mini+ takes a dip from the 24hrs of the original Mini to the current 12hrs. While it is indeed half the playing time, the gain of overall performance, which will be discussed later, does warrant the cost. So read on.


Size comparison (from left): digiZoid ZO2.3, FiiO E6, Mini+, Sandisk Sansa Clip+.

Sound Quality
A few more fun facts about the Mini+: instead of the TI’s DRV601 on the Mini, FireStone went with the MAX9722A this time. It is actually the same chip found on FireStone own Fireye HA, if I am not mistaken. I have seen this chip on a few portable amps now and it can go from fairly decent to really good, depends on the implementation. The RMAA measurement on the Mini+ is surprisingly good. Not the greatest, but really looks clean and distortion free, which is not always the case when it comes to volume-control-less, fixed volume boosting type of ultra-portable. Frequency response is flat from 20Hz to 20kHz – another improvement from Mini’s slightly roll-off bass. The output impedance is measured and calculated at 0.45ohm, which is a major improvement over the Mini’s 10ohm. Current output is quite good as well. Not the highest but far better than Mini and even comparable to many small portable amps. Overall, I’ll say the Mini+ is very solid as far as measurement goes.

Subjectively, the Mini+ doesn’t disappoint as well. As I have said on the original Mini – beside weaker bass, it compares quite well over FiiO E6 and digiZoid ZO2.3 and very close to what a mid-fi portable amp will sound like. The Mini+ really further improves upon it with a wider soundstage and an even more neutral and transparent presentation, which brings out more detail because of the improvement separation and cleaner positioning. Among the sub-$100 portable amp, I won’t say the Mini+ is able to compete head-to-head with the maxed out 18V Fred_fred_2004’s 3 Channels Headphone Amp just yet, but it is ready to level the playfield with a stock JDS Labs’ cmoyBB. Given the two are priced similarly and cmoyBB has been long regarded as an excellent sub-$100 portable amp of its own right, I’ll say the Mini+ is doing quite good as well. In exchange of a roll-able opamp, an independent volume control and more DIY’ish appearance of the cmoyBB, you get instead a smaller, more streamline package with mic+remote support of roughly the same sound quality. Those who use smartphone as their main source of music will definitely appreciate the Mini+ more.



EQ
The bass boost implementation on the Mini+ is almost identical to that of Fireye HD as the FR curve measured very similarly on both. FireStone Audio claims a +3dB boost @ 130Hz but as you can see, it is really more of a +4.5dB @ 130Hz and peak to almost +6dB under 50Hz. I bet FireStone Audio just center their FR curve around 500Hz as I usually center my graph near 1kHz. So essentially we are both right, but different in how we describe the same thing.

Overall the bass boost is quite solid and adds to the weight of bass hit without being overpowering.


Mini+, between Nano 7G and JVC HA-FXZ200.

Sum-up
It seems FireStone Audio has taken the lesson they have learned on the original Mini and applied it to the design of the Mini+. As much as you might think the Mini+ is more like a volume booster than a proper audiophile portable amp, it is nonetheless a fairly well rounded piece of audio gear. Among all the no-volume-control ultra-portable I have reviewed so far, beside the WoodWind which is still in development, Mini+ definitely comes the closest on blending small size, respectable spec and good sound quality into one device. This is quite a winner.

A thank to FireStone Audio for the sample

It seems there is a sudden surge of volume-control-less, fixed boost type of ultra-portable amps being released to the market in the recent months, likely targeting the smartphone users market which has seen enormous growth globally in the last few years. NuForce is following the trend and comes out with a small amp called the Mobile Music Pump, or MMP for short.



Spec
Audio Input: 1 x 3.5 mm
Headphone Output: 2 x 3.5 mm
Gain: 3X or 5X, selectable by user
THD+N: 0.09% @ 1 mW / 0.45% @ 32 mW
S/N Ratio: over 100 dB, 20 – 20 kHz A-Weighted
Frequency Response: 20 – 20 kHz +/- 1.5 dB
Max Output: 94 mW @ 32 ohm, 1.74 V, 10% THD+N / 49.2 mW @ 100 ohm, 2.2 V, 10% THD+N
Battery Life: over 8 hours, Rechargeable over microUSB port.
Battery Capacity: 200mAh
Charging time: 70 mins
Dimensions: 58.2 x 47.7 x 10 mm
Weight: 22g
MSRP: US$60





Accessories and Build Quality
MMP comes in a nice packaging that has some sort of an origami design. There are only two accessories to speak of - a short microUSB cable for recharging and a 3.5mm interconnecting cable.

The amp itself is fully plastic but appears to be fairly well built. The case is glued tight shut with a matte finishing, and nothing really spectacular to speak of. There is one 3.5mm input and two 3.5mm output, so it is possible for two headphone user to listen to the same source. However, be prepared to accept different loudness if the two of you are not using the same model of headphone or at least similar in sensitivity rating. There is a dedicated power switch and a power LED, which is great as I don’t really prefer amp that turn on/off automatically when headphone is inserted / unplugged. There is also a gain switch for selecting either a 3X or 5X gain. Both switches are slightly recessed so it is unlikely they will be flipped accidentally. That’s actually quite a nice touch.

Gain, Hiss and EMI
As mentioned, the MMP has two selectable gain settings, 3X and 5X, which is roughly equal to +10dB and +14dB in measurement. The amp itself doesn’t hiss at all, but has the tendency to pick up hiss from the source. So either you have to use a very clean sounding source, which is probably not quite practical, or avoid using hiss prone headphone. There is some audible EMI, which isn’t particularly bad but certainly isn’t particularly good either.





Sound Quality
As usual, some basic measurements have been carried and the result is actually pretty close to NuForce’s published spec. First, there is a very tiny bit of roll-off over the 10kHz that should be of no concern audibly. There is also a -1dB roll-off from 100Hz to 20Hz in low gain and it increases to -2.5dB in high gain. As high gain also measured noisier than low gain, my advice is to stick to low gain as much as possible. RMAA result seems to confirm, or at least put the number fairly close to NuForce’s own number. As far as the result is concerned, it is slightly noisier than other similar ultra-portable I have measured, but remain well under the 1% threshold. I would speculate that the worsen number has something to do with the relatively high level of gain on the MMP. Output impedance is measured and calculated to be just under 0.4ohm. Current output is slightly on the low side but should be plenty enough for most headphones that don't have a very low impedance.All and all, MMP is best suited for either a weak source or headphone with slightly higher impedance.



 

Last time when we take a look at Spider, they were mainly a cable and IEM company. Now however, their product range covers everything from full sized headphone and small portable amps, including the Surround Pro that will be reviewed here.
 

 
Spec
DSP: Dolby Pro Logic II
Input/Output: 3.5mm Audio Jacks
ADC Audio Performance:
93dB SNR
81dB THD
Sampling Frequency: 8Hz-96kHz
DAC Audio Performance:
100dB SNR
90dB THD
Sampling Frequency: 8Hz-96kHz
MSRP: US$90
 

 

 
Accessories and Build Quality
The amp itself comes fairly well packed. Inside, you will find the amp, a back-clip ‘holster’, a short TRRS-to-TRRS interconnecting cable, as well as a microUSB charging cable. The overall build quality is actually quite solid, though nothing really spectacular to write home about. It is mainly hard plastic with aluminum trimming. Due to the rounded protrusion on the back (which seems to be the battery compartment), the holster actually are front facing, but it shouldn’t really be an issue. Though the amp comes with a TRRS cable, it doesn’t actually support mic and remote pass-through. It would have been great if it did, as I would imagine the Surround Pro will most appeal to mobile device user, especially tablet and phablet user who like to watch movie. Beside the power switch, there only other switch is for selecting Normal, Music or Movie mode. Normal mode is basically a pass through function with no Dolby processing, while Movie and Music movie each has different Dolby optimization to create a virtual 5.1 surround sound.
 
If there is one thing I don’t like about the design, it will be the lack of power on/off indicator. The only LED on the device is for charging only, so if you forget that you have left it on or accidentally turn it on, the battery will be drained completely.
 

Surround Pro with the clip.
 

 
Gain, Hiss and EMI
So far we have been referring to the Surround Pro as an amp, but the fact is it is not much of an amp actually, as it has a -5dB gain in Normal mode. This means it actually reduces loudness instead of increasing it. The Movie and Music modes are no better as well. Hiss is actually fairly noticeable on the Surround Pro, especially in quiet passage and when music is not playing. Good thing is that it isn’t so loud that it is audible when music is playing. EMI is very mild, so not a problem at all.
 
Sound Quality
As usual, I gave the Surround Pro an RMAA test just to get some basic information. The device measures surprisingly good in Normal mode. Actually it isn’t that much of a surprise given it doesn’t really amplify the sound. I didn’t bother to measure it under Music or Movie modes as I don’t expect RMAA to measure them correctly. The output impedance is a very good 1 ohm, and the current output is actually quite good as well.
 

 

 

 
So if Surround Pro isn’t much of an amp, what is it? Well, it is pretty much a hardware EQ system tailored for soundstage enhancement, similar to the discontinued JVC SU-DH1 but with lesser features (plus lower price tag).  Basically the device converts the input analog signal to digital, toss in some Dolby Pro Logic II magic, and then reconverts it back to analog signal.
 
So how does it sound? Well, quite excellent actually. You can’t really treat it as an amp and want it to sound neutral or transparent. That’s not what the Surround Pro is about. But once you leave the perception of amp behind, you can start enjoy the 5.1 channels simulation. The truth is I really not sure how the 5.1 thingy works, but the surround sound effect is fairly convincing, especially for movie. Action film starts to really come alive on my smartphone with the Surround Pro and a pair of headphone. While music also benefits from the surround sound effect, I tend not to care as much about it. Yes, it is more fun to listen to stereo music with the effect – but I have no problem listen to stereo as well, given I am not seeking a particularly fun experience with music as much as I do with movie. Don’t get me wrong though, if you are really seeking for the extra fun element, the Surround Pro does deliver that aspect very well. The Music mode is however not the same as the Movie mode. Music mode tends to be more about get a wider, rounder, more forward and immersive soundstage, while Movie is really about the surround sound effect like a home theater system. There is no restriction on which mode you should use for what though – while I do recommend Movie mode for movie only, Music mode tends to work both ways, depends on how you like your music.
 

Surround Pro and Nano 7G
 
Sum-up
While I won’t classify the Surround Pro as an audiophile gears, it is still quite a useful gadget to your average headphone user in the current mobile entertainment era where you get to watch movie and video on-the-go.  To overcome the hiss issue and for proper voltage (volume) gain, I really suggest you use the Surround Pro in between the source and an amp, even a small one. It will be like infusing your setup with some well-tuned Dolby effect (*and not to be confused with the often over-the-top SRS WOW effect). Yes, you will be double amping - but as I have mentioned, the device itself does have a very clean RMAA result and therefore shouldn’t degrade the sound quality by much. Consider the fun and joy of good sounding entertainment on the other end, I’ll say it is quite worth it.
 
A thank to Spider International for the sample.

The headphone amp market in China, like its headphone market, is full of competition. Besides the bigger brands that have already made a name for themselves in the international market, there are still quite a few small companies and workshops that are highly regarded in the local market, yet remain relatively unknown to the outside world due to language barrier. Panda Audio is one such company – found in 2006 as more or less a DIY workshop, the company has earned respect among the Chinese audiophiles for producing some of the best sounding portable headphone amps around. Here we take a look at their latest flagship – the amp-S.
 

 

 
Spec
No official spec has been published on the amp-S, so we’ll skip this part. MSRP is around US$260
 
Build Quality
The amp is an early sample but it should be the same as the final retail version. Since it is a sample, it doesn’t come with any package and accessories so we are not going to cover those parts.
 
The build quality of the amp can pretty much be summed up as ‘bullet proof’. Though the design is not exactly fashionable, it is very solid and nothing really to compliant about. The amp is running on a pair of 9V to give it’s the 18V swing on the opamp. You can use rechargeable but you will need to find yourself a separate charger as the amp doesn’t take external power and isn’t rechargeable. One of the unusual parts is that the power LED is ultraviolet (*black light) and can double as a money checker.
 

 

The two blue switches on both side of the opamp are for global / zero-global feedback selection
 
Gain, Hiss, and EMI
The amp-S has a fixed gain of +9.6dB. There is a very mild ‘pop’ during startup. It isn’t very loud but it is better to turn the amp on before plugging in any headphone. Hiss performance is quite good as the amp is total silence with the most sensitive IEM (Shure SE530 in this case) before the volume knob turns over 12 o’clock. Even after 12 o’clock, hiss remains fairly low. Given the relatively high fixed gain, any headphone that requires that much volume will not likely to be sensitive enough to pick up hiss. EMI performance unfortunately isn’t great and can get loud when receiving call.
 
Sound Quality
As usual, my sound quality evaluation started with some measurements. But before we go into the measurements, there are a few aspects of the amp we need to cover. The first thing is that the amp-S runs on two 9V batteries that give it an 18V swing (which I assume is split to +/-9V). It also has 2 dual channel (stereo) opamp in roll-able DIP8 configuration. In fact, you can either stick to two stereo opamp or use four single channel opamp of your choice (4 x OPA627 for an example). The second thing is that the amp-S, like its predecessor the amp-K Pro, has a unique-to-Pandaudio’s design – a user selectable feedback topology. You can either set it to run in either global feedback or zero global feedback configurations. The topic of global vs. zero global feedback is a bit too deep to cover, but the amp is set to run in global feedback by default and it does sound and measure better that way. Last but not least, the amp also has transistor buffer output stage.
 

 
So how does the amp-S measure? Well, regardless of being in mode 1 or 2, the frequency response is flat from 20Hz to 20kHz. In the default mode 2, the RMAA result is quite good and almost comparable to the reference O2, except the IMD noise is slightly higher (0.059% to 0.024%). In mode 1, THD and IMD noise both increase significantly though far from being bad – around 0.2% and more comparable to the Elekit hybrid tube TU-HP01 that I recently measured. I never asked Pandaudio which mode is which but I assume mode 1 is zero global feedback as it is known that this kind of design will result in more noise. While noise does seem to increase by a lot from mode 2 to mode 1, the degree is so low that I actually didn’t notice any distortion in either mode. There is however very distinctive sonic difference between them and we’ll leave that discussion to the next paragraph. Output impedance is very low, measured and calculated to around 0.4 ohm. Current output is great, among the highest of any portable amp I have measured, likely thank to the transistor buffer stage. This means amp-S should behave quite well even with very low impedance load, though the relatively high fixed gain might not be the best for very sensitive IEM.
 

Size comparison (from left): JDS Labs O2, JDS Labs C5, amp-S, Meier Audio StepDance, C&C BH2.
 
Subjective listening is mostly done on mode 2 as I find it to be the better of the two. The biggest difference between mode 1 and mode 2 is that mode 1 is smaller in soundstage and more forwarded, almost makes it sounds lush and musical. Mode 2 on the other is a lot wider and specious. Volume matched and compared to the reference O2, amp-S (in mode 2) is almost just as colorless as far as frequency distribution goes. The main difference is between the two is amp-S sounds a bit more laidback and specious. It can almost be said that amp-S has extra depth and deeper, better layering. The speciousness also makes amp-S sounds just a fraction slower in transient and appear a little more relaxing in the overall presentation. The difference however isn’t vast and probably hard to notice if you are not doing an A/Bing. Beyond that, amp-S can be described as another top-of-the-line sounding portable amp. Those who find O2 just a tad too aggressive will probably like the amp-S as it is almost a mellowed out O2 with comparable performance.
 
Opamp Rolling
Since amp-S is designed to be opamp roll-able, I took the opportunity to try out a few combos.
 
LME49860 – the stock opamp. Good soundstage and well layered, neutral with a hint of warm
MUSES02 – warm, great texture but lost a bit of space
MUSES01 – similar to LME49860, more balanced and specious but only work in full battery
MUSES8820 – similar to MUSES02, not quite as textured or warm
MUSES8920 – warm to a bit dull
AD8397 – slightly warm, but otherwise good balance
LME49720 – very 3D sounding
OPA275 – decent but a bit laidback
OPA2604 – decent but slightly compressed in soundstage
OPA2209 – similar to OPA275
 
Surprisingly MUSES02, which often excels in most amps, fails to impress. While it is decent sounding, it does fall short compared to the stock LME49860. The MUSES01 on the other hand sounds excellent on the amp-S and probably is the best sound opamp I tried – but it will only work on full battery and thus not a practical choice (as MUSES01 minimum voltage requirement is +/-9V). Other opamp also fail to impress, except for LME49720 with an exceptional 3D soundstage. However, I won’t say LME49720 has a clearly better sound than the stock LME49860. At the end I think sticking to the stock opamp is probably the best choice.
 

MUESE01 in amp-S - great sounding, if only for a short while.
 
Sum-up
So the rumor is confirmed – Pandaudio does make some of the best sounding amp, and not just for the Chinese but also for the world standard. The real shame is that this is not an easy amp to find. As far as I know, it is pretty much exclusive to those who live in China for now, unless you have a way to buy from Taobao and ship it oversea.
 
For those of you who are interested in distributing the Pandaudio’s products (they also make ultra-portable amp btw), just drop me an email and I can forward the contact detail to you.
 
A thank to Panda Audio for the sample.

Elekit, or EK Japan, is a Japanese company that specializes in making educational electronic DIY kit and DIY tube power amplifier. I have a recent chance to hear their latest ‘22’ hybrid tube power amp driving a pair of CEntrance’s MasterClass 2504 desktop speakers quite beautifully on the Mook’s Headphone Festival in Singapore. The TU-HP01 under review, which also appears on the show, is the company first portable tube hybrid headphone amplifier.
 

 
Spec
Vacuum tube: 2 x Raytheon 6418
Frequency response: 10Hz - 65kHz
Recommended Headphone impedance: 16ohm - 32ohm
Power supply: 4 x AAA or 4 x AAA Ni-MH rechargeable batteries
Battery life: Approx.10 hours
Dimensions: W78 x H16 x D117 mm (excl. projections)
Weight: 125g (excl. batteries)
 

 
Accessories and Build Quality
The TU-HP01 comes in a fairly plain white box that one might confuse it to be a DIY kit at first look. But unlike most of Elekit’s offerings, this little tube hybrid is fully finished and only requires 4 AAA batteries to come to live. Inside the box, you will find the amp, a manual (in Japanese), a short 3.5mm interconnecting cable, an extra face plate, a hex key as well as an extra opamp.
 

 
Though the top of the housing has six holes, the vacuum tubes (2 x Raytheon 6418) used in the TU-HP01 don’t actually heat up (or light up) at all so they are mostly there for aesthetically reason. There is a small orange LED just underneath the tubes that will light up to give you the impression of a ‘tube grow’.  Since there is no heat issue on the amp, you can cover the holes up without affecting the performance. Elekit includes an extra upside-down face plate that will let you choose which way you want the top side of the amp to be – again, this is mostly for aesthetically reason, and probably lesser chance for any dust getting into the amp if the holes is facing downward / inward. The battery bay can be accessed by unscrewing the back plate without any special tool. But if you want to swap the opamp, you need to use the included hex key to open up the front. While the amp is fairly slim, it is however not small. It has a footprint just bigger than an O2 and half as tall. I’ll call that a little bigger than a typical full-size portable.
 

 
TU-HP01 comes with JRC MUSES8820 pre-installed, plus an extra TI OPA2604 if you feel like opamp-rolling. I have done some simple measurement on the socket and it seems to be running on +/-4.5V. So any opamp that can operate on that voltage should work. Some of Elekit’s suggestions of alternative opamp include LME49720, MUSES8920, MUSES02, NJM4580, NJM4560, and NJM3414 (we’ll cover opamp rolling on later discussion).
 
Overall the amp has excellent build quality. The design and finishing is probably among the best I have even seen on any portable amp - a likely reflection of the Japanese meticulous nature to their products.
 

 

 
Gain, Hiss, EMI and Microphonics
There are two gain settings on the TU-HP01. The low setting is about -2.2dB while the high setting is about +4dB. The limited range of gain means it really won’t drive high impedance headphone to a very loud volume, which is probably why Elekit only suggesting headphone impedance range of 16ohm ~ 32ohm. However, I think it should be fine with anything less than 150ohm (if not a bit more) as long as it has high sensitivity. There is almost no click-and-pop during startup or shutdown. Hiss is however quite noticeable on sensitive IEM though it doesn’t change with volume. EMI is also very noticeable, annoying but not excessively loud.
 
Beside hiss and EMI, there is also some detectable microphonics from the tube, especially if there is any kind of impact (even a soft one, like tapping a finger on the housing lightly) on or near the amp. While it isn’t loud by any mean, it can be picked up in quiet passage of the music with sensitive headphone. To make sure microphonics is as low as possible, you need to be sure that the amp is turned on gently and allows it to sit on the desktop without any disturbance. If you notice the microphonics starts to increase, turning the amp off and on again will help to tame it down.
 
While hiss and microphonics are both masked quite well during music playback, they are definitely detectable. So even though Elekit suggested using low impedance (16ohm to 32ohm) headphones with the TU-HP01, it would be best to avoid using too sensitive a headphone on the amp.
 

FR curve for TU-HP01 with both included opamp
 
Sound Quality
As I have said in my iFi Audio iTube impression, tube gears are always associated with noise and harmonic, especially when it comes to measurement. The TU-HP01 is no exception. While the RMAA result isn’t too bad, it certainly isn’t quite as nice looking as a full solid state amp. THD and IMD are around 0.2~0.3% - while not too bad on their own, they are significant higher than the reference 0.02% of the O2. Frequency response is mostly flat with a tiny roll off at both ends. There is an almost inaudible -0.5dB from 10kHz to 20kHz and a minor -1dB from 100Hz to 20Hz. Output impedance is measured and calculated to be about 4 ohm, which isn’t too bad. Current output isn’t particularly high, but it should be enough for not demanding headphone. Though the TU-HP01 has a roll-able opamp design, the measureable difference between different opamp is actually quite minimum. One thing I took notice during the measurement is that high input level tends to increase distortion level on the amp more significantly, which is understandable given the amp is running on 4 AAA batteries and could clip easier than amp that runs on high voltage. While actual listening doesn’t quite reveal any significant distortion, it is advisable to keep the input lower than a full scale 2Vrms if you can. If you are using an iPod with its 0.55Vrms line-out, then it shouldn’t be any problem.
 
Subjectively, at least with the default MUSES8820 installed, TU-HP01 doesn’t come out as a colored sounding amp at first impression. If anything, it is hard to tell that if it is more ‘tube’ or ‘solid-state’ sounding, if you believe in such a classification. The one thing that can be sure is that it is quite a beautifully sounding amp. Volume matched to the O2 with a pair of RE-0, the most noticeable difference between them is that TU-HP01 brings out more background detail to the front, making it a richer and more textured presentation. While that’s a phenomenon I have observed on a few tube gears in the past, the TU-HP01 doesn’t do it in very euphonic or romantic way. Rather it is more subtle, or should I say in a less ‘tubish’ fashion. A more minor difference between the two is that TU-HP01 is slightly more laidback in presentation, pushing everything just a hair further away and a bit more specious.
Beyond those, TU-HP01 is almost every bit comparable to O2 in sound quality, or any top quality portable in the same price bucket.
 

 
Opamp Rolling
While the above observation is done with the default MUSES8820, the amp does come with an extra OPA2604 and is compatible to opamp that can run on +/4.5V. So with the 8820 as reference, here are the impressions of some opamp I have tried in TU-HP01:
 
MUSES8820 – neutral to warm, well bodied and textured.
MUSES8920 – similar to 8820, but a tiny bit sharper and not as weighty.
MUSES02 – a refined and wider sounding 8820, excellently balanced with a hint of warm.
LM4562 – airy and open, most ‘solid-state’ sounding but not quite textured.
OPA2604 – tubish, warm and weighty sound.
AD8066 – fairly neutral, slightly sharp on treble
AD8397 – neutral, fairly rounded and nothing stands out
OPA2209 – similar to AD8066, more dynamic but also grainier
 
Surprisingly, the included OPA2604 turns TU-HP01 into a much more ‘tube’ sounding amp than I thought that amp is capable of. It is warm and very rich, if not just a bit slow. Another more ‘distinguishable’ opamp is the LM4562, which sounds almost too clean to a fault. The best sounding opamp is no doubt the MUSES02. It retains the same signature as 8820, but more refined and better layered, giving a grander and more specious presentation. Other opamp I tried sound quite decent in the amp as well, but fail to impress in any major way. Overall, I’ll suggest stick to the MUSE8820 as a general good performer that is quite suitable for different music genres or upgrade to the MUSES02 if you can.
 

Size comparison (from left): Tube Amp BL-2, TU-HP01, Leckerton Audio UHA-4, FiiO E12, FireStone Audio FireyeHD
 
In Sum…
Despite its flaws, I’ll still consider TU-HP01 an excellent amp with both a beautiful finish and a beautiful sound. It is not suitable for headphone that is very demanding, either in current or voltage, and definitely not for those who can’t stand any hiss or microphonics. It is, in other words, not quite a one-size-fits-all type of portable amp that will do everything right. But if you can live with those flaws, it is still a lovely amp to own, or at least worth a listen to.
 
A thank to both Elekit Japan and VKMusic.ca for arranging the sample.

Signature Acoustics is a brand created by the India based audio retailer Pristine Note. Their first offering is the Elements C-12 - an IEM that took them 18 months of R&D, completed with a full wooden housing and aims to deliver the best bang for the bucks with an estimated price of US$50~60 with international release.
 

 
Spec
Driver: 8 mm (CCAW) Dynamic
Impedance: 18 Ohms @ 1Khz
Frequency: 17 Hz to 20 Khz         
Sensitivity: 102 dB
Cable length: 1.2m (split length 28 cms)
Channel Imbalance: Less than 2.5% dB @ 1 Khz
 

 
Packaging, Accessories and Build Quality
The C-12 comes on a fairly innocent looking black paper box - nothing too fancy or eye catching at first look. Inside, you will find the IEM, 4 pairs of eartips (S, 2xM, L), a shirt clip, two set of filters, either leather or brass case, depends of what package you are paying. The leather case, which looks and smells like real leather (and probably is), will come standard with C-12. The brass case package will cost a few dollars more. Practicality wise, the leather case is probably the better choice. But the brass case does look very impressive in person and probably great as a jewelry case. Considered that the IEM itself has a fairly inexpensive price tag, both cases are rather outstanding addition that elevates the whole package. The extra filters are also another great addon. One set is the same as those installed on the nozzle, while the other is a denser variance (with higher acoustic impedance) to tune for a slightly different sound.
 
Build quality is above average. The whole wooden housing doesn’t look quite as good a finish as Crossroads’ Woody or ThinkSound’s models and probably be better with a darker lacquer, but it is still solid. The cable looks and feels quite durable with a similar twisted wires finishing like the early Branwavz M2, but with some minor memory effect. All and all, it isn’t the best I have seen in the price range but far from the worst either.
 

 
Sound Quality
The IEM has been given 50 hours of burn-in before the review.
 
C-12 sounds warm and smooth, with emphasis on lush and richness. Bass reaches down deep, but rolls off in lower sub-bass so it doesn’t quite have the deep rumbling sensation. It is however quite abundance in quantity from mid to upper bass, not particularly boomy though definitely presents at most time, and can almost be classified as bass dominance. Lower mid is lush and rich, which are the signature sound of wood housing. However, the upper mid to treble are a bit too polite, lacking sweetness, crispiness and sparkle to highlight the micro-detail and air, and in turn makes vocal, especially female, sounds smooth, if not a bit dull. It is however still slightly ahead of that of Brainwavz M2 or M3 in drawing out detail. With a few dB of treble boost however, C-12 can really shines. Despite restricted air, soundstage is still very good, and better on width than depth. It is probably benefited from the wood housing which from my own experience, always delivers a more specious, nicely resonated sound than metal. All and all, the C-12 compares well to the similarly priced (and also bass heavy) beyerdynamic XP1 as well as early Brainwavz models, which is not too shabby for any company’s first IEM. The lushness of the C-12 will most appeal to those who are looking for easy going and fatigue-free sound, especially if you don’t mind a bit of bass in the mix.
 

 
Verdict
Despite being in India, a country that is not known for having audiophile’s headphone company, Signature Acoustics is passing with flying colors with their firstborn, the Element C-12. While it isn’t the be-all-end-all by any long shot, it is a statement to show that the company does know what it is doing and able to produce an IEM that can stand shoulder to shoulder with the competition – and that’s something they can be proud of.
 
A thank to Signature Acoustics for the sample.

I reviewed the BL-2 from Tube Amp a while ago. It is a portable tube amp that is on the cleaner side of the presentation, which is quite different from the warmish, mellow sound that you would have expected from tube gear. Nevertheless, it is still an excellent sounding amp on its own. Now the company has released another portable amp to the market, the TA-1. What is unique about the TA-1 is that it is a full discrete amp - meaning instead of using fully integrated opamp, the circuit is composed mainly of individual transistors, resistors and caps. Priced around US$210 in China, TA-1 can be found between US$230~$250 outside of China.
 

 
Spec
Input Sensitivity: 220mV
Rated Output Power: 2 x 450mW
Frequency Response: 20Hz – 80kHz (-1dB)
THD: Less than 0.001% (1kHz, 2.5V)
SNR: More than 106dB
Recommended Headphone Impedance: 16 ~ 300ohm
Battery Life: Over 10 hours
Weight: 250g
Size: 110 x 70 x 25mm
 

 

 
Accessories and Build Quality
Unlike the BL-2 which has a more luxurious pleather box, the TA-1 comes only in white hard paper box. Inside, there are only the charger and a short, though good quality 3.5mm interconnecting cable. The charger, which is the same from BL-2, pumps out 13.8V. That means you have to carry it around when travelling in order to recharge the amp. The good news are that TA-1 runs much longer than BL-2 (10+hrs vs. 3.5hrs) and much colder. So travelling is much less an issue, even though the two share the same large housing and about the same weight.
 
Build quality is on par with its elder sibling the BL-2: solid, tank-like, and definitely not flashy or eye catching. As mentioned earlier, one of the main selling points of the TA-1 is its full discrete topology. You won’t find an opamp anyway in the circuit. As far as I know, there is only one other commercially available portable amp that employs a full discrete headphone amp circuit and it is the Audio-gd NFB-16. But given NFB-16 has the size of a small desktop amp (and larger than four TA-1 together), it is really hard to classify it as portable except for the fact that it does operate on battery.
 

 

 
Gain, EMI and Hiss
Maximum gain is at an exceedingly high +22.5dB, which is probably more suitable for slightly inefficient full size rather than overly sensitive IEM as you might not get pass 9 o’clock on the volume pot most of the time. We have seen the same issue on the BL-2 but at least BL-2 is lower in overall gain (+19dB). I really wish Tube Amp can implement a gain switch as given the majority of headphone out there don’t really need that much gain.
 
EMI is decent - audible but low enough not to be annoying or get into the way. There is a very faint hiss that is inaudible to most except for the most sensitive of IEM. Oddly enough that this very faint hiss will go away once the volume increases (*generally it is the opposite that happens), which I guess is a good thing.
 

 

Size comparison (from left): FireStone FireyeHD, FiiO E12, TA-1, Leckerton Audio UHA-4, BL-2.
 
Sound Quality
Let starts with some of the more objective aspects of the TA-1. First, the amp measured fairly flat on RMAA. It has a very slight incline going upward but it is so small (0.1~0.2dB) that it should be inaudible. There is a mild roll-off starting from 100Hz and slowly down to -1dB @ 20Hz, which means it is close to inaudible as well. Noise and dynamic range are good as well, but THD and IMD are on the higher side – still below 0.2% but considerably higher than the reference 0.02% of O2. Output impedance is measured to a decent 2~2.5ohm, and should be fine with most low impedance headphone. Output current is quite good and nothing to complain about.
 

 
Subjectively, and if I have to sum up TA-1’s sound in just one sentence – it is a tube sounding amp without a tube. That is of course made more interesting to the fact that BL-2, the TA-1 elder sibling, does have a tube inside but is probably too clean sounding to be associated as tube amp in a blind test. But TA-1 is by no mean a step down. In fact, I am personally much preferring TA-1 over BL-2 even though BL-2 is an excellent sounding on its own right. Volume matched and compared to an O2, it is obvious TA-1 comes out just a faction slower in transient. Music note is not quite as sharp, clean or as aggressive. There are however much more underlying texture on the TA-1 that fills up the space, much more so than BL-2. The same texture can also be found on O2, but mostly fainted away, hiding in the background between the instruments. TA-1 in contrast will enrich this background information in a subtle way and brings them forward without any twisting and obvious coloration. It works out almost the same way as how a vacuum tube amp will add to the richness of the music without being protrusive, an effect similar to what I have heard recently on the iFi Audio iTube. Because of the mellow and euphonic nature of the presentation, TA-1’s soundstage doesn’t come out quite as wide and well defined as O2. It is not small per se either – it is just that there is some much texture in between, that soundstage tends not to stand out as particularly important aspect. In a way, it is more about being immersive rather than pinpoint accurate when it comes to how it handles image and positioning.
 

TA-1 (left) and BL-2 (right)
 

The inner-working
 
In Sum…
All and all, TA-1 comes close as a top-tier / near top-tier portable amp. Technically it is not as tight as a true top-tier amp that is designed purely from measurement. But it is not sounding so colored that it is hard to enjoyable either, at least not to the casual users who are not strictly limiting themselves to the most transparent of gears. If anything, TA-1 strikes a good balance being musical, if not euphonic sounding while staying relatively neutral – obviously, it is not going to appeal to purists who are seeking a wire-with-gain solution. If you are however interested but still not totally sure about having a portable tube amp, then TA-1 will definitely be quite a good alternative to consider.
 
A thank to Tube Amp for the sample.
 
[UPDATE] The TA-1 reviewed here is the original/older batch. The newer batch, which I have not heard, is said to come with 10% lower gain and less imbalance in lower volume so it will go better with sensitive IEM.

iTube is the latest addition to iFi Audio ‘Micro’ line of audio gears. On one hand, it inhere the same minimalistic concept as the other Micro gears; on the other hand, it is a departure from the previous all-solid-state design. If anything, it is the first in Micro gears that will appeal more toward speaker user rather than headphone user. So what exactly does an iTube do? In essence, it is a tube buffer / pre-amp, with some extra features threw in.



Spec
Input voltage: AC 100-240v, 50/60Hz
Power consumption: under 4W Idle, 10W max
Input impedance: 1M ohm Direct Tube Buffer / 100k ohm Pre Amplifier with Volume Control
Output stage output impedance: less than 1 ohm
Corrected output impedance: Less than 200 ohm
Dimensions: 175(l) x 67 (w) x 28 (h) mm
Weight: 278g (0.61lbs)
MSRP: US$299





Gain - Buffer or Pre-amp
Like the newer iCAN, there is a user selectable gain switch on the belly of the housing. However, the switch also enable / disable the volume pot on the iTube, allowing it to run either as a Class A tube buffer or a pre-amp. In both modes, you can also choose either zero or +6dB gain, depends on how strong your source’s signal is. Of course, you will have to take into account whether the output will clip the input of the next device (which will be an amp or an amp section on an active speaker). My suggestion is, if your source has a 2V line level signal or something near it, keeps it at zero gain. If your source has a weak signal (i.e. older iPods only have only a 0.55V line-out), gives it the +6dB gain.

As for whether to use it as a pure buffer or pre-amp will depend on the gears you are connecting the iTube to. If it is feeding to a power amp that has no volume control of its own, then obviously you should use iTube in pre-amp mode to control the volume. If however the iTube is feeding into an active speaker that has its own volume control, then iTube should be configured as buffer. Note that the volume pot also doubles as the on/off switch, so you still need to turn it on even in the buffer mode, though volume will not be changed at all. As with all tube gears however, you should try to avoid rapid or frequent on/off action as much as possible in order to prolong the tube operational lifespan. If you are only going away for a short while, instead of turning it off, it might be better just to leave it on.



Sound Quality
Tube is always associated with noise and harmonic – in a way iTube is about those as well, but more on the harmonic and less on the noise. For measurement, I set the iTube up in a full iFi chain – staring with iUSB Power, which connected to the iDAC via the Gemini dual head USB cable. The line-out of the iDAC is fed into the iTube as a buffer, then to the iCAN with a 23.5 ohm dummy load. RMAA measurement is done with both the iTube in chain and without it for the comparison. Surprisingly, the impact of iTube, at least on graph, seems to be fairly minimum. Yes, it is noisier with the iTube, but we are talking about 0.001% of difference in THD and 0.004% in IMD+Noise, plus less than 2dBA in overall noise level. The numbers are small enough that I have to wonder how valid they will be in actual listening. As far as the frequency response goes, iTube is as flat as it can be, at least when the Digital Antidote Plus is not engaged (*but we will leave that discussion to the next section).

The actually listening experience with iTube however is a much less subtle business. Beside the setup mentioned above (plus a pair of Sony MDR-1R and a few IEM), most of my audition of the iTube is done in buffer mode with a pair of Creative GigaWorks T40 Series II 2.0 desktop speaker with an additional Creative sub-woofer. The first thing to pick up with the iTube, and particularly noticeable with headphones, is the distinctive ‘tube’ sound. So what is this tube sound? Well, it is a general richness that isn’t there before, like switching from a standard definition to a high definition signal on TV. It is the same image, but there is more information that fills up the space. At first, the effect is not that apparent. But once I switched back from iTube+iCAN to iCAN only, and just like going from HD to SD signal, everything sounds duller and harsher, even though I have been enjoying iCAN by itself for months now. I guess this is what iFi has referred as the ‘voodoo’ of the tube sound - the kind of euphonism that is just hard to get rid of once you are hooked. This is probably what makes tube gear user return to tube time and time again.



EQ
There are two additional features that are packed into the iTube – the 3D HolographicSound (3DHS) System and Digital Antidote Plus – well, calling the Digital Antidote Plus an EQ might not be the most accurate, but just bear with me here.

Don’t confuse the 3DHS on the iCAN to iTube. Yes, both have the same name and supposed to enhance soundstage, but that’s just about where the similarities end. The 3DHS on the iCAN is tuned with headphone in mind, but the one on iTube is all about speaker. The ‘small’ setting is meant for floor speakers or monitors that are already placed far apart and the goal is to put out a better perceived separation on the lower frequency region. The ‘wide’ setting however is meant for desktop monitor (such as PC speaker) and is aimed to project a bigger overall image than the speaker usually can. You can of course choose whichever setting that fits your own speaker configuration and taste, but I do find the wide setting does show significant improvement over my T40 S-II (which is a desktop speaker). In a way it does a similar function as the software based virtual surround sound effect built into the Windows OS, but much better in result. While Windows (and a good number of software movie players) tends to try to create a more hollowed out image between the left and right speakers to create the illusion of space, the 3DHS ‘Wide’ on iTube is more about pushing out an image larger than the speaker’s physical placement, as if they are actually further apart. This works out better for music listening as the mid-range still retains its texture and intensity as opposite to a hollowed out sound. As with the 3DHS on iCAN, I am quite amazed by iFi ability to fine tune the analog circuit and be better than software solution. But the one thing to note is that this 3DHS is for speaker only. Trying to use it with headphone will mostly mess up the image instead of improving it (same can probably be said on iCAN’s 3DHS negative effect on speaker).



Digital Antidote Plus on the other hand is lesser of an EQ and more of a phase correction technique for digital source. The original idea of a ‘digital antidote’ comes from and patented by Anthony Taddeo of Taddeo Speakers in the early 90s to address the digititis of then popularized CD system. In simple terms, it involves splitting the analog signal from a digital source into two, delays one of them with a few milliseconds then recombines it back to the original signal in order to correct whatever phase error introduced in the digital stage and to recreate a ‘more analog like’ music reproduction. It had caused quite a stir in the audiophile’s community when it was first introduced, both positively and negatively, where some swear by it while other found the effect to be subtle at best. With the passing of Mr. Taddeo about 10 years ago and his company dissolved subsequently, the original Digital Antidote and the V2 hardware are no longer available. The Digital Antidote Plus (DAP) in the iTube is however a new take on the original concept and according to iFi, updated to be compatible to the latest and upcoming HD format of music.

So history asides, does the DAP work as advertised? Well, the first thing I did is to get some measurement off. RMAA is really not great on measuring beyond the basic stuff and certain not for phase - but one thing to look for is the treble roll-off that inheres from the original Digital Antidote circuit. As you can see from the graph, the area around 8kHz is actually bumped up by 0.4dB, then it drops off to -1dB around 15kHz before ending up at -2.5dB @ 20kHz. Given human is only sensitive to about 1dB of SPL change, the actual effect will be more noticeable above 15kHz. But since most human, especially adult, have likely lost a significant amount of hearing on the high treble region, the actual impact on listening should be relatively small. In real listening, my 30+ years-old ears really didn’t detect any major loss of treble from album to album. One thing I do pick up, and in a very obvious fashion, is the increase of texture and detail in the mid to bass range. This is most noticeable when I was listening to Piano Guys’ first and second album, where the decay and body of the piano and cello becoming unusually clear and their timbre becoming almost too good. To use the TV analogy again, it will be the equivalent of switching from HD to a 4K signal - Okay, perhaps this all seems to be too much of a hype. But it really isn’t about how SD to HD, or how HD to 4K that matters. It is about the increase of overall information from one to the other. With the iTube alone, it is like filling the background with all the missing notes. With the DAP engaged, it is like those notes are brought to the foreground. Is that how ‘analog sound’ should be, or is it a better approximation of live music that is somehow lost in the recording process in the digital era? I truly have no answer. But I can say I don’t dislike it. It is something that I can leave it on all the time and don’t feel like it has degraded the sound in any way. In fact, I think the result is really a plus to the overall music listening experience – regardless of whether it is an EQ, a phase correction or just another technological voodoo.

One last thing to note is that I can pick up the difference on DAP easier on the headphones than on the speaker. Then again, my headphones are generally better sounding and more revealing than my speaker. Your mileage however might differ.



…in Conclusion
I have a very small computer desk that also doubles as my working and listening area, and it is constantly full of all kind of gears and never enough in space. Early last week after receiving the iTube, I had the whole iFi chain setup on the desk for the iTube review and thought that I would have to disassemble them quickly in the next few days in order to reclaim the space back. The whole setup, as I am about to finish writing this review, is still sitting on the desk after almost 2 weeks. It could very well be staying there for a while longer, given how much music I have been enjoying recently over my Creative speaker - and to think that I am predominately an on-the-go IEM user. I guess this really sum up the iTube magic thingy. Sometime it is the seamlessly little stuffs that add up to make the whole experience worthwhile.

A thank to iFi Audio for the review sample